dean1997sport
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Thats pretty cool!
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Explorer 4.0 OHV - system too lean banks 1 & 2 Please HELP!!!
- Thread starter stikz
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Thats pretty cool!
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German Engineer
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Hello everyone let me revive this old thread here because I currently also just have this Problem.
There are some advices posted here already and numerous people keep replacing more or less expensive parts that aren't necessarily the cause, while tracking the issue down.
Well the best general advice I can give you when you have these lean codes, is by starting with the cheap and less costly things and measures first then passing on to the more expensive ones.
Lets be frank, these cars are pretty old by now and almost anyone who drives them isn't keen on unnecessarily wasting a lot of money to keep it running.
So the first and cheapest is definitely by starting to check for Vakuum leaks!
And when you do that make sure to check ALL of the numerous vacuum hoses.
This car does have an awful lot of them!
And they really run all over the engine compartment. Some even go all the way down underneath the battery on the front right, others all the way down underneath the air filter to an Air Conditioning Control device which is really well hidden and you can probably best access from underneath the car by removing the inner plastic covers of the fender. And also don't forget to check if that huge rubber tube from the air filter to the Intake manifold is really installed properly and air tight and doesn't have a visible crack or hole anywhere.
It's really not uncommon for old vacuum hoses to be broken or even just to have came loose from someone accidentally pulling on it, while doing repairs on the car, or from not being reinstalled properly after repair works in the first place.
Of course it's a bit of a hassle to thoroughly check all of those vacuum hoses, but its not really any sort of difficult or tricky thing to do and it really has big potential for an incredibly cheap repair of the problem.
It can certainly save you a lot of money otherwise wasted on unnecessarily replacing sensors or Valves or whatever devices - or even having them replaced by a repair shop one by one!
As I said, this car really does have an awful lot of vacuum hoses. My Explorer Sport even has a really nice schematic vacuum hose diagram on a sticker right at the front when you open the hood. It tells you a lot about where vacuum hoses all go from and to in this car.
But somehow even this really nice and very helpful and informative diagram doesn't quite each and every single one of the vacuum hoses on it either. It's just mostly complete not perfectly complete, but it's very helpful to see where to look for vacuum hoses and possibly leaking devices nonetheless.
The other really cheap and efficient way to check for Vakuum leaks is the
smoke test with a cigar. Others already mentioned that and there is a video about it posted here already.
(Even being a nonsmoker myself and having to cough a lot whenever doing a cigar smoke tests by myself, I strongly recommend to do the testing with a cigar and to really just forget the otherwise fairly commonly suggested Carb-cleaner Spray test. The cigar smoke just works MUCH better and its much more efficient and last but not least poses much less of a fire hazard. And if you don't smoke yourself you'll certainly have a friend who does and who might actually enjoy being employed as human smoke machine.)
This kind of smoke test really does work brilliantly.
And a very good way to do it on the Explorer, is by detaching the end of the big vacuum hose that goes to the Brake Booster and sticking a smaller transparent hose that's long enough inside it to blow smoke into the engine while moving around looking for leaks. (The Brake Booster is on the driver side all the way back by the windshield, that huge round black Metal - tank or half bubble kinda looking thing where a hose from the intake manifold runs to. If that basic explanation helps increase any possible confusion
)
You can get a plastic hose that nicely fits inside the bigger vacuum hose running from the intake manifold to the brake Booster at any reasonably assorted Home Depot. Just stick and push it in a few inches and it will already seal itself up enough to blow cigar smoke inside the engine just by sticking in there half what firmly.
When you do the Cigar smoke test, just make sure you really don't blow any sort of cigar particles or tobacco in there and try not to let all too much saliva get into the manifold either.
If you see smoke coming out of a little pressure valve on the "Idle Air Control Bypass Valve" which itself is a device mounted on the Intake manifold, don't think that means you have to replace that entire part. But other than that any smoke you see coming out anywhere is pretty certainly a vacuum leak of some kind.
And if there is a leak anywhere, smoke blown into the intake manifold can come out of the strangest places. Remember all those vacuum hoses are connected to places all over and via the vacuum connection to the engines oil reservoir the smoke - respectively air coming in the other way around through a vacuum leak - can actually even find its way through some pretty surprising passages.
So please do look carefully and thoroughly to make sure you spot any smoke that might come out of all the various places connected via all those numerous vacuum hoses located pretty much almost anywhere all over the engine compartment.
You really don't want to miss a vacuum leak in the test and then naturally end up falsely convinced that it must certainly be something else that is causing the problem of the lean codes.
Another next thing that's cheap and easy to check is, if the Mass Airflow Sensor is dirty. And cleaning that with MAF sensor cleaner spray certainly won't do any harm on an old car either and may very well be helpful or necessary.
And if you know a tiny little bit about electronics and have a Multimeter at hand, you might possibly also do some basic testing to check if the MAF-sensors electric circuit seems functional.
To diagnose the Fuel injection System you'll need to get a Fuel Pressure Test Kit. You should be able to get one for 45 Dollars or cheaper.
I will refrain from posting further detailed instructions on how and what exactly to do to diagnose the fuel Injector system with a pressure tester here, because messing with fuel does have it's fire safety aspects.
But with a Fuel Pressure Tester you can get further Information that helps find out if any fuel injectors are leaky or the Fuel Pressure Dampener is broken or leaking or if the Fuel Pump or Filter might be clogged or not working properly.
What you might as well just do without getting a fuel Pressure Tester - since its and older car and could very likely use a new one sooner or later anyways - is simply just replacing the fuel filter.
The Explorer usually has a metal tank and when that is old it might be rusty inside and a clogged fuel filter can of course also cause low fuel pressure and thus cause lean codes.
And replacing a fuel filter is still cheaper than buying Fuel Pressure Test Kit after all.
And the risk of any money being wasted when replacing a Fuel Filter is naturally near 0, unless the car does have a new filter of course.
Now those things I mentioned here are certainly some really cheap and low cost tests and repairs you may fairly easily be able to do yourself, even without being a car repair genius yourself and you also won't need fancy tools to check those things out.
And should you happen to find a vacuum leak that way which you aren't capable of repairing yourself, then you at least know where and what exactly it is and then you can have a repair shop repair just specifically that for you and you will much less likely end up with someone replacing parts that don't mandatorily need to be replaced to keep the car running fine and safe for another while.
I hope this post does help at least one or another of the readers here in avoiding unnecessary costs that occur when randomly replacing parts that may potentially be causing the Lean codes issue.
There are some advices posted here already and numerous people keep replacing more or less expensive parts that aren't necessarily the cause, while tracking the issue down.
Well the best general advice I can give you when you have these lean codes, is by starting with the cheap and less costly things and measures first then passing on to the more expensive ones.
Lets be frank, these cars are pretty old by now and almost anyone who drives them isn't keen on unnecessarily wasting a lot of money to keep it running.
So the first and cheapest is definitely by starting to check for Vakuum leaks!
And when you do that make sure to check ALL of the numerous vacuum hoses.
This car does have an awful lot of them!
And they really run all over the engine compartment. Some even go all the way down underneath the battery on the front right, others all the way down underneath the air filter to an Air Conditioning Control device which is really well hidden and you can probably best access from underneath the car by removing the inner plastic covers of the fender. And also don't forget to check if that huge rubber tube from the air filter to the Intake manifold is really installed properly and air tight and doesn't have a visible crack or hole anywhere.
It's really not uncommon for old vacuum hoses to be broken or even just to have came loose from someone accidentally pulling on it, while doing repairs on the car, or from not being reinstalled properly after repair works in the first place.
Of course it's a bit of a hassle to thoroughly check all of those vacuum hoses, but its not really any sort of difficult or tricky thing to do and it really has big potential for an incredibly cheap repair of the problem.
It can certainly save you a lot of money otherwise wasted on unnecessarily replacing sensors or Valves or whatever devices - or even having them replaced by a repair shop one by one!
As I said, this car really does have an awful lot of vacuum hoses. My Explorer Sport even has a really nice schematic vacuum hose diagram on a sticker right at the front when you open the hood. It tells you a lot about where vacuum hoses all go from and to in this car.
But somehow even this really nice and very helpful and informative diagram doesn't quite each and every single one of the vacuum hoses on it either. It's just mostly complete not perfectly complete, but it's very helpful to see where to look for vacuum hoses and possibly leaking devices nonetheless.
The other really cheap and efficient way to check for Vakuum leaks is the
smoke test with a cigar. Others already mentioned that and there is a video about it posted here already.
(Even being a nonsmoker myself and having to cough a lot whenever doing a cigar smoke tests by myself, I strongly recommend to do the testing with a cigar and to really just forget the otherwise fairly commonly suggested Carb-cleaner Spray test. The cigar smoke just works MUCH better and its much more efficient and last but not least poses much less of a fire hazard. And if you don't smoke yourself you'll certainly have a friend who does and who might actually enjoy being employed as human smoke machine.)
This kind of smoke test really does work brilliantly.
And a very good way to do it on the Explorer, is by detaching the end of the big vacuum hose that goes to the Brake Booster and sticking a smaller transparent hose that's long enough inside it to blow smoke into the engine while moving around looking for leaks. (The Brake Booster is on the driver side all the way back by the windshield, that huge round black Metal - tank or half bubble kinda looking thing where a hose from the intake manifold runs to. If that basic explanation helps increase any possible confusion
)You can get a plastic hose that nicely fits inside the bigger vacuum hose running from the intake manifold to the brake Booster at any reasonably assorted Home Depot. Just stick and push it in a few inches and it will already seal itself up enough to blow cigar smoke inside the engine just by sticking in there half what firmly.
When you do the Cigar smoke test, just make sure you really don't blow any sort of cigar particles or tobacco in there and try not to let all too much saliva get into the manifold either.
If you see smoke coming out of a little pressure valve on the "Idle Air Control Bypass Valve" which itself is a device mounted on the Intake manifold, don't think that means you have to replace that entire part. But other than that any smoke you see coming out anywhere is pretty certainly a vacuum leak of some kind.
And if there is a leak anywhere, smoke blown into the intake manifold can come out of the strangest places. Remember all those vacuum hoses are connected to places all over and via the vacuum connection to the engines oil reservoir the smoke - respectively air coming in the other way around through a vacuum leak - can actually even find its way through some pretty surprising passages.
So please do look carefully and thoroughly to make sure you spot any smoke that might come out of all the various places connected via all those numerous vacuum hoses located pretty much almost anywhere all over the engine compartment.
You really don't want to miss a vacuum leak in the test and then naturally end up falsely convinced that it must certainly be something else that is causing the problem of the lean codes.
Another next thing that's cheap and easy to check is, if the Mass Airflow Sensor is dirty. And cleaning that with MAF sensor cleaner spray certainly won't do any harm on an old car either and may very well be helpful or necessary.
And if you know a tiny little bit about electronics and have a Multimeter at hand, you might possibly also do some basic testing to check if the MAF-sensors electric circuit seems functional.
To diagnose the Fuel injection System you'll need to get a Fuel Pressure Test Kit. You should be able to get one for 45 Dollars or cheaper.
I will refrain from posting further detailed instructions on how and what exactly to do to diagnose the fuel Injector system with a pressure tester here, because messing with fuel does have it's fire safety aspects.
But with a Fuel Pressure Tester you can get further Information that helps find out if any fuel injectors are leaky or the Fuel Pressure Dampener is broken or leaking or if the Fuel Pump or Filter might be clogged or not working properly.
What you might as well just do without getting a fuel Pressure Tester - since its and older car and could very likely use a new one sooner or later anyways - is simply just replacing the fuel filter.
The Explorer usually has a metal tank and when that is old it might be rusty inside and a clogged fuel filter can of course also cause low fuel pressure and thus cause lean codes.
And replacing a fuel filter is still cheaper than buying Fuel Pressure Test Kit after all.
And the risk of any money being wasted when replacing a Fuel Filter is naturally near 0, unless the car does have a new filter of course.
Now those things I mentioned here are certainly some really cheap and low cost tests and repairs you may fairly easily be able to do yourself, even without being a car repair genius yourself and you also won't need fancy tools to check those things out.
And should you happen to find a vacuum leak that way which you aren't capable of repairing yourself, then you at least know where and what exactly it is and then you can have a repair shop repair just specifically that for you and you will much less likely end up with someone replacing parts that don't mandatorily need to be replaced to keep the car running fine and safe for another while.
I hope this post does help at least one or another of the readers here in avoiding unnecessary costs that occur when randomly replacing parts that may potentially be causing the Lean codes issue.
jawknee99
Member
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- February 25, 2016
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- 2000 explorer sport ohv m
hey guys
Heres the deal.
150,000 miles on my explorer running great until i got the famous po171 po174 codes.
Had my truck sitting for a good while then finally
Changed my
Coil pack, spark plugs wires, spark plugs. Oil, oil filter air filter and of course your intake gasket. Something told me to change the injectors but figured. Hey my car cant be that much in bad shape. Put everything back together what do you know. Worst engine performance ever. No power misfiring, car as red and got. Thinking i had the wrong firing order double checked triple checked. I had it right.
There i go to change my cats only changed 2 btw...the big ones. Coming back home a little better but still no power. I knew i should've changed my injectors since day 1. New injectors plus new gasket under the fuel rail. Btw all my gaskets were im really good shape so are all of my vacuum and evap hoses.
So now here i am with a ton of new parts. Got the fuel filter but couldnt get it off . Couldnt wait till the auto store opened so i figured hey what the heck. Turned it on runs like hell again full power. Everythings good till i get those damn codes again.
Finally changed the fuel filter which was dirty af. Ran it more same codes.
I smoked out my intake with a homemade machine and no leaks from any places ...im stuck now what... help
Heres the deal.
150,000 miles on my explorer running great until i got the famous po171 po174 codes.
Had my truck sitting for a good while then finally
Changed my
Coil pack, spark plugs wires, spark plugs. Oil, oil filter air filter and of course your intake gasket. Something told me to change the injectors but figured. Hey my car cant be that much in bad shape. Put everything back together what do you know. Worst engine performance ever. No power misfiring, car as red and got. Thinking i had the wrong firing order double checked triple checked. I had it right.
There i go to change my cats only changed 2 btw...the big ones. Coming back home a little better but still no power. I knew i should've changed my injectors since day 1. New injectors plus new gasket under the fuel rail. Btw all my gaskets were im really good shape so are all of my vacuum and evap hoses.
So now here i am with a ton of new parts. Got the fuel filter but couldnt get it off . Couldnt wait till the auto store opened so i figured hey what the heck. Turned it on runs like hell again full power. Everythings good till i get those damn codes again.
Finally changed the fuel filter which was dirty af. Ran it more same codes.
I smoked out my intake with a homemade machine and no leaks from any places ...im stuck now what... help
German Engineer
Well-Known Member
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- February 2, 2016
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- 181
- Reaction score
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- Year, Model & Trim Level
- 1999 Explorer Sport 2WD
Well, with all those parts you threw at it already I suggest You try thoroughly figuring out what the issue is before throwing anymore random parts at it.
The things that come to my mind which it seems you haven't tried yet, are the following things:
A bad or dirty Mass Airflow Sensor.
A problem with the EGR System EGR Valve.
Or a problem with the fuel delivery.
Faulty O2 sensors (but probably rather unlikely, because there is one for each bank)
I suggest You get or loan an OBD2 scanner and look at the live data and freeze frame data. From looking at the live data on a good OBD scanner You can get an idea if the MAF is giving reasonable values. And from looking at the freeze frame data you might be able to get an idea if its a lean condition under load or under idle. It might take more than one freeze frame data to get some certainty if the lean condition is predominantly under idle conditions (where the vacuum is maximum) or under load (with the fuel injectors open and a dropping fuel pressure). ((With needing more than one set of freeze frame data, I mean clearing the error codes and checking and comparing all the freeze frame data whenever the codes come up again and again to get an idea of the operating conditions of the vehicle when the codes come up. You might also try resetting the PCM now and then, during the process of diagnosing the lean codes from the freeze frame data, by detatching the battery for a while to make the car relearn the driving parameters.) You should be able to get a pretty good idea if the lean codes tend to come on rather when the engine is at idle or also when it is under load fairly soon, when collecting and comparing freeze frame data.)
You can also get an idea if the O2 sensors appear to be working properly from interpreting the livedata.
And the Explorer also runs some on board tests of the EGR system. You can see the results of those in the IM readiness tests when they are completed as well as in some of the Information provided in the manufacturer specific test section under Mode $6.
To diagnose the fuel pressure you can loan or buy a fuel pressure test kit. Those do not have to be very expensive.
Should the fuel pressure be low you might possibly have a bad fuel pump. (Or an electric problem with the fuel pumps power supply or ground).
Your really badly clogged up fuel filter might be an serious indication to a problem with rust inside your gas tank and that could of course make your fuel pump go bad as well.
Below is a really good and video You might want to watch regarding the diagnosis of the MAF sensor, and the freeze frame data to determine the type of lean condition, as well as diagnosing a fuel pump. Even though the guy in this video has professional equipment you probably won't get a hold of yourself, most of the information he used can also be gained with regular OBD2 scanners of the kind those major auto pars shops offer as service for their customers to use for free.
Going along that route of further diagnosing the issue is my suggestion of a "battle plan".
Here's the YouTube video from ScannerDanner:
www.youtube.com/watch?v=nYN-RoFVwAA
Good luck!
Macgiobuin
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Forward Catalytic converter (one of them) broke down and got blown down to the common downstream catalytic converter. After it stalls and then cools, the powdered ceramic material falls down and suddenly you can run again. Separate the input pipe that goes into the downstream (common) converter, and if the common converter is full of cat junk, that's your problem. But which one upstream failed? And why did it fail? Possibly a bad fuel injector, either stuck open (causing a rich condition, which the computer tries to fix by starving all 3 cylinders on that bank of fuel), or stuck closed, (causing the computer to fix by richening up all 3 cylinders, which leaves 2 cylinders running real rich, causing the cat on that side to burn up and disintegrate.) Nevertheless, check the downstream converter for being clogged. I pulled mine off and turned it input side down and a pile of junk came down like an avalanche. So if you replace it with a new one, now will it happen again? Here's where you gotta check for bad fuel injectors, bad fuel pressure regulator/housing....
darrell milgrim
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Had same problem and it was ground wire going to fuel pump in the tank.Tech run a new ground wire from the battery to fuel pump and it has been three months no more problems.
Chaztschida
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Glad im not reviving a 6 year old thread lol but i had all these types of issues in my 01.. 3 days after i bought it it died i had $2000 and a baby comin in a couple weeks so yeah i threw parts at it...but what actually fixed it for me was a combination of a fuel pump, fuel filter, plug wires, plugs (All brand new) and a can of starting fluid. The fuel pump and filter got clogged up with nasty old fuel and destroyed it which in turn wrecked my plugs which killed the wires..
darrell milgrim
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Your luck sounds alot like mine.i had same problem and it was 40psi fuel pressure on rail while running.I have replaced almost everything except fuel damper on fuel rail.
herlilred96
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Hello all,
I just wanted to say thank you to everyone on here.
After months of struggling with a darn #4 misfire and bank one lean condition this forum helped me narrow it down and finally I have all green on the readiness monitors and no pending codes....
Mine is a 96 4.0 v6 ohv.
First I changed out the coil pack, plugs and wires.
New radiator, water pump, fan clutch and thermostat. (Unrelated to codes)
Then I had this terrific moaning coming from under the hood.
Replaced the iac and fixed that issue.
Than I went ahead and changed the pcv, egr valve, and the dpfe hoping to cure the lean to no avail...
Finally after much reading here I decided I would give it one last try and changed out the intake gasket and voila all readiness monitors are reading green on the code reader and all codes are clear with nothing pending. Monday I will get the smog check done and I am back on the road with enough new parts that it should be good to go for another year or two.
Tomorrow I pull the dash apart again and change the rest of the dash lights that have all burned out one by one...
I wasn't going to fix that if the thing was never going to pass smog.
By the way if your having a low compression issue which I had on cylinder 4, I strongly recommend a product called "Restore". Call it snake oil if you must but it made my compression come up significantly and my misfire went away shortly after I put it in.
Good luck all. again thanks for all of the great info here.
I just wanted to say thank you to everyone on here.
After months of struggling with a darn #4 misfire and bank one lean condition this forum helped me narrow it down and finally I have all green on the readiness monitors and no pending codes....
Mine is a 96 4.0 v6 ohv.
First I changed out the coil pack, plugs and wires.
New radiator, water pump, fan clutch and thermostat. (Unrelated to codes)
Then I had this terrific moaning coming from under the hood.
Replaced the iac and fixed that issue.
Than I went ahead and changed the pcv, egr valve, and the dpfe hoping to cure the lean to no avail...
Finally after much reading here I decided I would give it one last try and changed out the intake gasket and voila all readiness monitors are reading green on the code reader and all codes are clear with nothing pending. Monday I will get the smog check done and I am back on the road with enough new parts that it should be good to go for another year or two.
Tomorrow I pull the dash apart again and change the rest of the dash lights that have all burned out one by one...
I wasn't going to fix that if the thing was never going to pass smog.
By the way if your having a low compression issue which I had on cylinder 4, I strongly recommend a product called "Restore". Call it snake oil if you must but it made my compression come up significantly and my misfire went away shortly after I put it in.
Good luck all. again thanks for all of the great info here.
hellzombi
New Member
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- January 11, 2018
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- 5
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- 0
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- California
- Year, Model & Trim Level
- 1998 Ford Explorer Sport
That is a great post! I'm having some lean bank issues. Now I know where I'm gonna start first. Thanks!Hello everyone let me revive this old thread here because I currently also just have this Problem.
There are some advices posted here already and numerous people keep replacing more or less expensive parts that aren't necessarily the cause, while tracking the issue down.
Well the best general advice I can give you when you have these lean codes, is by starting with the cheap and less costly things and measures first then passing on to the more expensive ones.
Lets be frank, these cars are pretty old by now and almost anyone who drives them isn't keen on unnecessarily wasting a lot of money to keep it running.
So the first and cheapest is definitely by starting to check for Vakuum leaks!
And when you do that make sure to check ALL of the numerous vacuum hoses.
This car does have an awful lot of them!
And they really run all over the engine compartment. Some even go all the way down underneath the battery on the front right, others all the way down underneath the air filter to an Air Conditioning Control device which is really well hidden and you can probably best access from underneath the car by removing the inner plastic covers of the fender. And also don't forget to check if that huge rubber tube from the air filter to the Intake manifold is really installed properly and air tight and doesn't have a visible crack or hole anywhere.
It's really not uncommon for old vacuum hoses to be broken or even just to have came loose from someone accidentally pulling on it, while doing repairs on the car, or from not being reinstalled properly after repair works in the first place.
Of course it's a bit of a hassle to thoroughly check all of those vacuum hoses, but its not really any sort of difficult or tricky thing to do and it really has big potential for an incredibly cheap repair of the problem.
It can certainly save you a lot of money otherwise wasted on unnecessarily replacing sensors or Valves or whatever devices - or even having them replaced by a repair shop one by one!
As I said, this car really does have an awful lot of vacuum hoses. My Explorer Sport even has a really nice schematic vacuum hose diagram on a sticker right at the front when you open the hood. It tells you a lot about where vacuum hoses all go from and to in this car.
But somehow even this really nice and very helpful and informative diagram doesn't quite each and every single one of the vacuum hoses on it either. It's just mostly complete not perfectly complete, but it's very helpful to see where to look for vacuum hoses and possibly leaking devices nonetheless.
The other really cheap and efficient way to check for Vakuum leaks is the
smoke test with a cigar. Others already mentioned that and there is a video about it posted here already.
(Even being a nonsmoker myself and having to cough a lot whenever doing a cigar smoke tests by myself, I strongly recommend to do the testing with a cigar and to really just forget the otherwise fairly commonly suggested Carb-cleaner Spray test. The cigar smoke just works MUCH better and its much more efficient and last but not least poses much less of a fire hazard. And if you don't smoke yourself you'll certainly have a friend who does and who might actually enjoy being employed as human smoke machine.)
This kind of smoke test really does work brilliantly.
And a very good way to do it on the Explorer, is by detaching the end of the big vacuum hose that goes to the Brake Booster and sticking a smaller transparent hose that's long enough inside it to blow smoke into the engine while moving around looking for leaks. (The Brake Booster is on the driver side all the way back by the windshield, that huge round black Metal - tank or half bubble kinda looking thing where a hose from the intake manifold runs to. If that basic explanation helps increase any possible confusion
You can get a plastic hose that nicely fits inside the bigger vacuum hose running from the intake manifold to the brake Booster at any reasonably assorted Home Depot. Just stick and push it in a few inches and it will already seal itself up enough to blow cigar smoke inside the engine just by sticking in there half what firmly.
When you do the Cigar smoke test, just make sure you really don't blow any sort of cigar particles or tobacco in there and try not to let all too much saliva get into the manifold either.
If you see smoke coming out of a little pressure valve on the "Idle Air Control Bypass Valve" which itself is a device mounted on the Intake manifold, don't think that means you have to replace that entire part. But other than that any smoke you see coming out anywhere is pretty certainly a vacuum leak of some kind.
And if there is a leak anywhere, smoke blown into the intake manifold can come out of the strangest places. Remember all those vacuum hoses are connected to places all over and via the vacuum connection to the engines oil reservoir the smoke - respectively air coming in the other way around through a vacuum leak - can actually even find its way through some pretty surprising passages.
So please do look carefully and thoroughly to make sure you spot any smoke that might come out of all the various places connected via all those numerous vacuum hoses located pretty much almost anywhere all over the engine compartment.
You really don't want to miss a vacuum leak in the test and then naturally end up falsely convinced that it must certainly be something else that is causing the problem of the lean codes.
Another next thing that's cheap and easy to check is, if the Mass Airflow Sensor is dirty. And cleaning that with MAF sensor cleaner spray certainly won't do any harm on an old car either and may very well be helpful or necessary.
And if you know a tiny little bit about electronics and have a Multimeter at hand, you might possibly also do some basic testing to check if the MAF-sensors electric circuit seems functional.
To diagnose the Fuel injection System you'll need to get a Fuel Pressure Test Kit. You should be able to get one for 45 Dollars or cheaper.
I will refrain from posting further detailed instructions on how and what exactly to do to diagnose the fuel Injector system with a pressure tester here, because messing with fuel does have it's fire safety aspects.
But with a Fuel Pressure Tester you can get further Information that helps find out if any fuel injectors are leaky or the Fuel Pressure Dampener is broken or leaking or if the Fuel Pump or Filter might be clogged or not working properly.
What you might as well just do without getting a fuel Pressure Tester - since its and older car and could very likely use a new one sooner or later anyways - is simply just replacing the fuel filter.
The Explorer usually has a metal tank and when that is old it might be rusty inside and a clogged fuel filter can of course also cause low fuel pressure and thus cause lean codes.
And replacing a fuel filter is still cheaper than buying Fuel Pressure Test Kit after all.
And the risk of any money being wasted when replacing a Fuel Filter is naturally near 0, unless the car does have a new filter of course.
Now those things I mentioned here are certainly some really cheap and low cost tests and repairs you may fairly easily be able to do yourself, even without being a car repair genius yourself and you also won't need fancy tools to check those things out.
And should you happen to find a vacuum leak that way which you aren't capable of repairing yourself, then you at least know where and what exactly it is and then you can have a repair shop repair just specifically that for you and you will much less likely end up with someone replacing parts that don't mandatorily need to be replaced to keep the car running fine and safe for another while.
I hope this post does help at least one or another of the readers here in avoiding unnecessary costs that occur when randomly replacing parts that may potentially be causing the Lean codes issue.
hellzombi
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- 1998 Ford Explorer Sport
Thanks to everyone for the great posts and tips. I too got the "Check Engine" light. I'm gonna try some of the tips mentioned to see what might be wrong with my car. It's not running too bad though I do notice I'm getting poor gas mileage. I decided to post so that I might help anyone out there having the same issue. I will post my progress and further developments as they come.
hellzombi
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- 1998 Ford Explorer Sport
Hello everyone! After I replaced my alternator my check engine light turned off. I spoke with a friend of mine who is a Ford mechanic. I told him about the problems I was having. He recommended I clean my idle control valve with some carburetor cleaner. That sometimes the mechanism gets stuck due to build up. I did it and my RPM's dropped and the my car idle got a little smoother. The car is running better too. I'll probably do a couple of other things to make it run better. I'll post it when I do. This is what I cleaned
Here is a pic of my idle
Here is a pic of my idle
Davidmoore1206
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- 1999 Ford Explorer Xlt
The fuel pressure damper(special ford name for fuel regulator but can only be found by the name ford gives it) could be the issue I replaced mines last year to fix the rough idle and I also replaced a evap hose that connects to under the throttle body close to the throttle plate because it was brittle
C420sailor
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Zombie thread
ashner19
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- 2001 Explorer Sport Stock
Good thread tho! I started a new one with the same problem last month. Finding this would’ve been helpful and eliminated the need for my new thread on the subject.
C420sailor
Explorer Addict
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- 98 XLT SOHC, 99 EB 5.0L
Agreed, I just don’t want people wasting time trying to diagnose a problem that has either long been fixed or isn’t ever going to be fixed.
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