Rough idle and "Check Engine Soon" light - FIXED

[fyfeman]

I cleaned out the battery wires...the RPMS aren't jumping anymore but when you look at the needle you can see that the needle/RPMS want to jump/bounce up and down..it seems to be working alittle better, I have also realized that when I take my oil cap off it is milky color. I was told thats the head gasket, could this be causing the RPMS to jump/bounce as well?

 

[joesacamano]

Thanks,
i'm off to autozone - i don't know how long my tape is going to hold.

Testament... not long enough

Also, if you are out and the hose is leaking so bad the engine will hardly run, take the hose off the drivers side valve cover (same 90 degree hose) and install on throttle body. Will get you home!

 

[joesacamano]

The guys at the ford parts counter were like "you had better use this factory part, a coolant bypass hose will break down from the oil. It's a different type of rubber"... I'm like DUDE!!!!!!!!!!!! there are gobs of these vehicles that are failing like this....... because FORD used the RIGHT kind of rubber????? I'm thinking my $3.50 coolant bypass hose will last longer than the $40.00 factory assembly (8 yrs)....

 

[joesacamano]

I'm closing out this thread with some additional information some of you, specifically with 2002 4.6L V-8 engines, might find interesting.

I had a hell of a time trying to locate just a replacement rubber elbow. I did a little research on the web concerning rubber elbows used on vaccum systems on Ford products. I discovered this is a very common problem not just in Explorers but all Ford autos using the rubber elbows. I don't know why you can not buy just the rubber elbow from Ford. They make you buy the entire assembly that uses the rubber elbow.

I went to my local Ford dealer's parts department thinking that if I have to buy the whole assembly then I'll just do it and consider myself lucky since I was able to self diagnose and repair my rough idle problem so easily. The parts department punched in on their computer parts inventory system the year, model, engine type and even the VIN number to pull up a diagram of my engine's emission control system with parts diagram. It looks like this:

They ordered the assembly labelled 6C324 insisting that this was what I needed and pointed out that the drawing even shows the rubber elbow plugging into the throttle body. When the part arrived it was ridiculously obvious that that assemble was not correct. Thinking it must be the other assembly in the picture labelled 6A664 they ordered that one. When the second assembly arrived it was also obvious that it would not fit my engine. They were baffled and said they didn't have a clue as to why neither assembly would fit. In the end they suggested I go to a junk yard and retreive a rubber elbow off a junked Explorer.

I called a couple of junk yards but no one had a 4.6L V-8. I then went to NAPA and Carquest in search of a rubber elbow. Neither place had them and neither place had a clue as to where to get one expect to insist that my local Ford dealer was the only place with such replacement parts.

I ended up going to a different Ford dealer to see if they were a little more on top of their game. I ended up going throught the same "riga-ma-roll" as I did with the first Ford dealership. Both dealerships were just baffled and at a loss as to an explanation as to why they could not find the right replacement parts. Finally, a fella at the second dealership got the idea of trying to locate an engineering number off of the original assembly. Thankfully, with a little digging around in my engine compartment he was able to cut off a tag on the original assembly with an engineering ID.

Confident he was easily going to figure out this mystery he plugged in the engineering ID into his computer only to find that this number doesn't exist for a 2002 Explorer. In fact, for some reason he was unable to locate the actual part number for this assembly. A crossed referenced part number to the engineering ID would have allowed him to get a list from the computer of all the cars that use the assembly. In the end, on a whim, he walked back to the parts bins that contained a hodge-podge collection of emission control vacuum assemblies and started looking for one that matched my original. By some stroke of luck he actually found an assembly matching that of the one on my engine.

Finally, not only did we have what I needed but we also had the part number of the assembly. The parts guy punched the identified part number in the computer to find out what cars used this assembly. To our amazement this is what was displayed:

Mustang - years 2002, 2003, 2004
Explorer/Mountaineer - years 2003, 2004

The only thing I can think of is that my vehicle is a March 2002 build and therefore has a 2003 engine configuration. I've heard of mid-year production changes but this was ridiculous because the drawings on the Ford computer systems didn't reflect this change nor were there any notes. What is really disappointing is that the Ford dealership pulled up the emission control engineering drawing for a 2003 Explorer and it looked identical to a 2002. Anyone with at least a 2002 or 2003 V-8 that uses the pictured PCV vacuum tube assembly is going to have the same problem I had locating a replacement.

If any of you have a 2002, 2003, or 2004 Explorer or Mountaineer with a 4.6L V-8 and are having the same issue with replacing the PCV vacuum tube assembly and it looks like mine you'll want to have your dealer to order:

Part Number 2L2Z 6A664 BA
Motorcraft KCV-129
Engineering ID Number 2L2E 6K817-BC

In the end I'm glad I replaced the entire assembly. The rubber fitting that plugs onto the PCV value on the other side of the tube was starting to deteriorate too. Because of my troubles, the parts guy at the second Ford dealership sold me the vacuum tube assembly for $16.17 instead of charging me the normal $28.76 price. He also sold me a Motocraft PCV valve for $9.05 instead of charging me the normal $16.09 price. I figured that with 91K miles I might as well change the PCV valve while changing out the vacuum tube assembly.

Lastly, the X is running normal...no rough idle problems and no Check Engine light. Who would have thought that that hole in the rubber elbow on that vacuum line could cause those 7 Check Engine codes?

Hose 6767 in the illustration (goes to driver's side valve cover) above appears to be the same hose that is deteriorating on the throttle body. Possibly could purchase it instead of the entire PVC assy.

I purchased a 90 degree hose from Autozone PN#70001 (4.99) and cut one end. Fit perfectly! Hose is relatively heavy duty... has reinforced cord in it. Sales guy let me go behind counter and select the one I needed. I'll keep an eye on it and report back. As for those that are posting, 'should use original part because it is made for application', well... sorry. This part is failing on every 4.6L. The only variable is time! The hose I purchased is much heavier and if it is neoprene rubber, it will outlast original part.

Cleaned MAS (doesn't need to be removed. Can spray cleaner on it with top of air filter box removed.) Cleaned IAC (easily done) Cleaned Throttle body ans she purrs like a kitten. Engine very smooth during idle. Best it's ran in a long time. Check engine light is out. Hope this helps along with all the posts. Thanks to all for reporting experiences and saving us money!

 

[goosechace]

This is what I have going on guys. Rough idle so I started looking for a vacuum leak and found these and I know where the go. The line comes from the back side of the manifold.

 

[393stroker]

I'm closing out this thread with some additional information some of you, specifically with 2002 4.6L V-8 engines, might find interesting.

I had a hell of a time trying to locate just a replacement rubber elbow. I did a little research on the web concerning rubber elbows used on vaccum systems on Ford products. I discovered this is a very common problem not just in Explorers but all Ford autos using the rubber elbows. I don't know why you can not buy just the rubber elbow from Ford. They make you buy the entire assembly that uses the rubber elbow.

I went to my local Ford dealer's parts department thinking that if I have to buy the whole assembly then I'll just do it and consider myself lucky since I was able to self diagnose and repair my rough idle problem so easily. The parts department punched in on their computer parts inventory system the year, model, engine type and even the VIN number to pull up a diagram of my engine's emission control system with parts diagram. It looks like this:

They ordered the assembly labelled 6C324 insisting that this was what I needed and pointed out that the drawing even shows the rubber elbow plugging into the throttle body. When the part arrived it was ridiculously obvious that that assemble was not correct. Thinking it must be the other assembly in the picture labelled 6A664 they ordered that one. When the second assembly arrived it was also obvious that it would not fit my engine. They were baffled and said they didn't have a clue as to why neither assembly would fit. In the end they suggested I go to a junk yard and retreive a rubber elbow off a junked Explorer.

I called a couple of junk yards but no one had a 4.6L V-8. I then went to NAPA and Carquest in search of a rubber elbow. Neither place had them and neither place had a clue as to where to get one expect to insist that my local Ford dealer was the only place with such replacement parts.

I ended up going to a different Ford dealer to see if they were a little more on top of their game. I ended up going throught the same "riga-ma-roll" as I did with the first Ford dealership. Both dealerships were just baffled and at a loss as to an explanation as to why they could not find the right replacement parts. Finally, a fella at the second dealership got the idea of trying to locate an engineering number off of the original assembly. Thankfully, with a little digging around in my engine compartment he was able to cut off a tag on the original assembly with an engineering ID.

Confident he was easily going to figure out this mystery he plugged in the engineering ID into his computer only to find that this number doesn't exist for a 2002 Explorer. In fact, for some reason he was unable to locate the actual part number for this assembly. A crossed referenced part number to the engineering ID would have allowed him to get a list from the computer of all the cars that use the assembly. In the end, on a whim, he walked back to the parts bins that contained a hodge-podge collection of emission control vacuum assemblies and started looking for one that matched my original. By some stroke of luck he actually found an assembly matching that of the one on my engine.

Finally, not only did we have what I needed but we also had the part number of the assembly. The parts guy punched the identified part number in the computer to find out what cars used this assembly. To our amazement this is what was displayed:

Mustang - years 2002, 2003, 2004
Explorer/Mountaineer - years 2003, 2004

The only thing I can think of is that my vehicle is a March 2002 build and therefore has a 2003 engine configuration. I've heard of mid-year production changes but this was ridiculous because the drawings on the Ford computer systems didn't reflect this change nor were there any notes. What is really disappointing is that the Ford dealership pulled up the emission control engineering drawing for a 2003 Explorer and it looked identical to a 2002. Anyone with at least a 2002 or 2003 V-8 that uses the pictured PCV vacuum tube assembly is going to have the same problem I had locating a replacement.

If any of you have a 2002, 2003, or 2004 Explorer or Mountaineer with a 4.6L V-8 and are having the same issue with replacing the PCV vacuum tube assembly and it looks like mine you'll want to have your dealer to order:

Part Number 2L2Z 6A664 BA
Motorcraft KCV-129
Engineering ID Number 2L2E 6K817-BC

In the end I'm glad I replaced the entire assembly. The rubber fitting that plugs onto the PCV value on the other side of the tube was starting to deteriorate too. Because of my troubles, the parts guy at the second Ford dealership sold me the vacuum tube assembly for $16.17 instead of charging me the normal $28.76 price. He also sold me a Motocraft PCV valve for $9.05 instead of charging me the normal $16.09 price. I figured that with 91K miles I might as well change the PCV valve while changing out the vacuum tube assembly.

Lastly, the X is running normal...no rough idle problems and no Check Engine light. Who would have thought that that hole in the rubber elbow on that vacuum line could cause those 7 Check Engine codes?

How about on an 02 EB Explorer with a v-6 4.0 engine? Mine idles around 600, shuts off sometimes at stop lights, revs up to 2k on some start up's, and I've cleaned iac, replaced air filter, replaced fuel filter, cleaned mass air meter, and still idles low and it also seems like it skips a beat or want to shut off while driving slow in the snow when it snows here and I think when it does that the idle drops and jumps back up.

 

[Rrunkle]

I had to replace my iac on my 03 limited. The autozone versions did not work. Only OEM, motor craft.

 

[393stroker]

I had to replace my iac on my 03 limited. The autozone versions did not work. Only OEM, motor craft.

My thing is that I don't want to replace to much and none be my problem. It's possible that it might need to be replaced and won't hurt to replace it. I like to find out for sure what's causing this then buy the part. Thanks

 

[denny seifried]

Really glad I came upon this thread. My 2003 Explorer XLT with a 4.6 threw the two, lean bank codes. Good thing I didn't listen too much to the Advance guy (cat converter & O2 sensors) and started doing a Google-search and came upon this thread. After the code was set, the engine did not run very well, with some rough idle and a very strange way it would settle back to idol, after revving it up. I ran almost like the accelerator was sticking, also.

As soon as I studied the photos of the PCV hose, I went out and took the plastic cover off the engine and my hose looked exactly like the hose in the photo. It was caved in and maybe split, slightly. I decided to save some money and try this repair, myself. I chose to go the Ford/Motorcraft way and get a "factory" hose. I tried area Ford dealers and none showed the hose in stock and would need a special-order, which would come in, next day. I also tried a local, KOI parts house; as, I know they carry a very complete line of Motorcraft parts. I had used KOI for previous Motorcraft parts I needed, and, one of the sales associate was a former student of mine. He always took care of me on parts from KOI. Their delivery was at least 3-5 days; so, I wanted to get this Explorer running and went with a local Ford-store.

I, also, decided I would replace the PCV valve; as, it was due at 100K and I am pushing 130K. I knew it had never been changed; so, went on a search for the proper valve. Nobody carried those; however, just on a chance, I was going by O'Reilly and stopped in. The parts-guy looks it up in the computer and came out with this metal one with the inlet at a 90-degree angle, for just a couple of bucks. I knew that was not the correct one and sent him looking at the computer screen. Oh, yes, he did find a Motorcraft PCV and it was the correct-one. He would have to order it in, for next-day delivery. Those Motorcraft valves are close to $20. These PCV's on the 4.6 use a bayonet socket in the valve cover.

BTW, when I went to the Ford Part Department, they told me the PCV hose has been updated and has a new number and a new price (higher, of course!) Here are the new numbers:

Ford Parts Number-----------2L2Z-6A664-FA

Motorcraft Number-----------KCV-240

The only change in the Ford number were the last, two, letters (FA) is new; while, the Motorcraft number is an entirely, new, part-number. FWIW, the design has changed. Those, two, angled ends of the PCV-hose are made out of a different material than the original, rubber angle-connector. The new hose angle-bends are some type of flexible plastic. They should stand-up better than the OEM original hose. Looks like these will not collapse so easily, let's all hope!

The parts guy felt sorry for me and gave me a discount, which brought the cost back to around $35 for the PCV hose! I decided to replace the air filter and clean the MAF. I took the large-diameter clamps loose and removed the air hose with attaches to the air cleaner box and to the throttle-body. I removed the air filter (it was pretty dirty) and gave the MAF a blast of MAF liquid cleaner. On the other end, I shot some throttle-body cleaner around the front of the throttle-body and into the throttle, the best I could.

All of this cleaning and putting everything back together, couldn't have taken more than 15 or 20 minutes. The most difficult process was getting that old PCV hose loose from the manifold connection. No way would that hose pull right-off the connector, like it did on the PCV valve. I needed to get a sharp box cutter and make some cuts at the end of the hose, get a screw driver and pry the hose off that connector. It is just like dealing with a stuck heater hose!

Thanks, again, for those of you who got this thread originally going and telling us what to look for.

 

[ladonin]

Rubber 90 at Hardware store?

Hey...thanks for all the info. Could you go to a hardware store and buy a rubber 90 in the plumbing department? And split it on the underside to patch over it, then secure it with a couple of hose clamps??

 

[JoshMcMadMac]

I had the P1151 code show up intermittently, and fuel economy was noticeably worse than usual. My PCV line did need replaced, but did not resolve the code. I kept looking and found that my driver-side fuel injector(s) were leaking. I grabbed a pack of FelPro injector o-rings from AutoZone...$4 for four o-rings! The resolved my issue, but I made sure to measure an o-ring before using them. The are size #203 o-rings, which can be had for ~$6 as a 25 pack from McMaster-Carr or Amazon.com. Get the viton material version and you will be all set, should this be your issue too.

 

[Pontisteve]

This is a good thread, since this PCV elbow problem exists on many Ford products. I thought you guys might like a little better explanation of what is happening, and why.

The oil that's in the entire PCV system breaks down the rubber hose over time. The hose is special emissions-friendly stuff, which means its oil resistant, but clearly its not resistant enough. Ford figures this sort of thing out over time (just like we do), and fixes things with updated parts. The original 2L2Z-6A664-BA part number being replaced with a -FA part number (Motorcraft KCV-240) makes sense, as does a previous comment about how the line is now plastic.

As oil deteriorates this hose, it softens up from the inside out. Even if you don't see a problem with your hose externally, it may be very soft and collapsing under high manifold vacuum (idle and deceleration causes high manifold vacuum). Eventually, it will break and you will have a vacuum leak.

A better way to describe this would be an 'unmetered air' leak. Ford uses a mass air system, and the MAF meter (bolted to your air filter box) reads ALL air going into the engine. It tells the PCM how much air is flowing into the motor, by sending it a voltage between .5 and 5 volts. More air = more volts. When air is able to sneak into the engine without going thru the MAF first, this causes the MAF to read less air, it tells the computer that, and the computer adds less fuel. At idle, this is a LOT less. As you raise engine RPM, this becomes a smaller percentage of overall airflow and has a lesser effect. That's why it runs better at higher speeds.

Coolant hoses are not oil resistant, and make a poor choice for a patch. The emissions/fuel hoses are oil resistant, and will hold up much longer.

I developed a small hole in my 03 Explorer 4.6 pcv elbow, and when I tried to pull the hose off to inspect it, it made the hole rather big. When I hooked my scantool to it, I was amazed to see short term fuel trims rise to +66%, where they seemed to be maxed out at. That is a LOT of extra fuel, and is being added to replace what the MAF isn't seeing. Normally, cars are generally limited to about a 30% max correction, which is why I was amazed.

The long term trims will eventually learn the adjustment, and the short term trims won't have to work as hard. Once you fix the vehicle, you will see the short term trims go negative (taking fuel away), and the long term trims will eventually get the message and go down. Whenever you see the LTFT and STFT going the opposite direction, it means you fixed an air/fuel ratio problem and the car is currently correcting a previously learned fuel trim.

The oxygen sensor codes are all basically saying the same thing. The engine is lean. When you see both O2 sensors responding the exact same (and large) way, it's not an O2 sensor issue. It's a problem with fueling or a vacuum leak. All those O2 codes are really describing the same problem, that the O2 signal is fixed lean, the car is lean, the O2 is not switching back and forth between lean and rich, etc. One look at the STFT and you will see that's a problem, and the other codes are just a bi-product of that huge short term fuel trim. Fuel trims should always be under 10%, preferably under 5%.

You can erase all codes by disconnecting the battery for a few minutes. This will also erase all learned fuel and idle trims though. So the car will have to learn all of it's trims all over again. Honestly, this isn't really a good thing. You're better off not doing this, and just letting the car relearn the correct trims at, and just above, idle.

When you reset codes on a Ford with a scantool, you are not erasing those learned trims (called Keep Alive Memory, or KAM). So that's a good way to go here. Or just don't do anything. The check engine light and codes will go away after 40 drive cycles on their own once you fix the problem.

 

[AshleyT]

I'm having the same problem with my 2002 explorer 4.0 V6. Autozone told me it was more than likely a vacuum hose as well. I just had the transmission rebuilt in it yesterday and before I dropped it off at the place it wasn't doing this but since I have picked it back up it idles rough then dies. The transmission place says they know they didn't cause it because they don't work close enuff to the hoses. Any advice

 

[biglare3]

ive been having a hard idle problem now for a while in my 02 ex 4.0 v6...never really looked at it because of no time but the rpms did drop a few times this week when i was stopping... good write up too bad i got the 4.0 lol

 

[biglare3]

the 4.0 has the same elbow, mine had a hole large enough that you could loose a wrench in it. Just remove the top piece that reads 4.0 liter and look at the front passenger side of the engine, the hole will be obvious.

 

[flavin]

Just want to give this guy props, it's the exact solution to my problem, and I own a 2003, so I am lucky that I won't get the 'rigamaroll'. Thanks SyberTiger

I'm closing out this thread with some additional information some of you, specifically with 2002 4.6L V-8 engines, might find interesting.

I had a hell of a time trying to locate just a replacement rubber elbow. I did a little research on the web concerning rubber elbows used on vaccum systems on Ford products. I discovered this is a very common problem not just in Explorers but all Ford autos using the rubber elbows. I don't know why you can not buy just the rubber elbow from Ford. They make you buy the entire assembly that uses the rubber elbow.

I went to my local Ford dealer's parts department thinking that if I have to buy the whole assembly then I'll just do it and consider myself lucky since I was able to self diagnose and repair my rough idle problem so easily. The parts department punched in on their computer parts inventory system the year, model, engine type and even the VIN number to pull up a diagram of my engine's emission control system with parts diagram. It looks like this:

They ordered the assembly labelled 6C324 insisting that this was what I needed and pointed out that the drawing even shows the rubber elbow plugging into the throttle body. When the part arrived it was ridiculously obvious that that assemble was not correct. Thinking it must be the other assembly in the picture labelled 6A664 they ordered that one. When the second assembly arrived it was also obvious that it would not fit my engine. They were baffled and said they didn't have a clue as to why neither assembly would fit. In the end they suggested I go to a junk yard and retreive a rubber elbow off a junked Explorer.

I called a couple of junk yards but no one had a 4.6L V-8. I then went to NAPA and Carquest in search of a rubber elbow. Neither place had them and neither place had a clue as to where to get one expect to insist that my local Ford dealer was the only place with such replacement parts.

I ended up going to a different Ford dealer to see if they were a little more on top of their game. I ended up going throught the same "riga-ma-roll" as I did with the first Ford dealership. Both dealerships were just baffled and at a loss as to an explanation as to why they could not find the right replacement parts. Finally, a fella at the second dealership got the idea of trying to locate an engineering number off of the original assembly. Thankfully, with a little digging around in my engine compartment he was able to cut off a tag on the original assembly with an engineering ID.

Confident he was easily going to figure out this mystery he plugged in the engineering ID into his computer only to find that this number doesn't exist for a 2002 Explorer. In fact, for some reason he was unable to locate the actual part number for this assembly. A crossed referenced part number to the engineering ID would have allowed him to get a list from the computer of all the cars that use the assembly. In the end, on a whim, he walked back to the parts bins that contained a hodge-podge collection of emission control vacuum assemblies and started looking for one that matched my original. By some stroke of luck he actually found an assembly matching that of the one on my engine.

Finally, not only did we have what I needed but we also had the part number of the assembly. The parts guy punched the identified part number in the computer to find out what cars used this assembly. To our amazement this is what was displayed:

Mustang - years 2002, 2003, 2004
Explorer/Mountaineer - years 2003, 2004

The only thing I can think of is that my vehicle is a March 2002 build and therefore has a 2003 engine configuration. I've heard of mid-year production changes but this was ridiculous because the drawings on the Ford computer systems didn't reflect this change nor were there any notes. What is really disappointing is that the Ford dealership pulled up the emission control engineering drawing for a 2003 Explorer and it looked identical to a 2002. Anyone with at least a 2002 or 2003 V-8 that uses the pictured PCV vacuum tube assembly is going to have the same problem I had locating a replacement.

If any of you have a 2002, 2003, or 2004 Explorer or Mountaineer with a 4.6L V-8 and are having the same issue with replacing the PCV vacuum tube assembly and it looks like mine you'll want to have your dealer to order:

Part Number 2L2Z 6A664 BA
Motorcraft KCV-129
Engineering ID Number 2L2E 6K817-BC

In the end I'm glad I replaced the entire assembly. The rubber fitting that plugs onto the PCV value on the other side of the tube was starting to deteriorate too. Because of my troubles, the parts guy at the second Ford dealership sold me the vacuum tube assembly for $16.17 instead of charging me the normal $28.76 price. He also sold me a Motocraft PCV valve for $9.05 instead of charging me the normal $16.09 price. I figured that with 91K miles I might as well change the PCV valve while changing out the vacuum tube assembly.

Lastly, the X is running normal...no rough idle problems and no Check Engine light. Who would have thought that that hole in the rubber elbow on that vacuum line could cause those 7 Check Engine codes?

 

[Pontisteve]

I replaced mine a while back too. It's just the elbow that goes bad, where it connectors to the throttle body. Spraying a little water in and around that area with the engine idling will quickly reveal if you have this problem. I think the whole hose assembly was like 35 bucks. It'll probably only go bad once in the lifetime of the vehicle, and there isn't a good cheap fix for it that fits perfectly. It's best to just get a new one from Ford.

 

[jorijnsmit]

Symptoms seem similar; too low idling for the first minute or two after cold start.

My engine (1998 Limited 4.0L SOHC) is of a different layout though and I can't find the elbow described.

Made sure the air vents I could find are attached properly (you can see the black duct tape on the exits after the MAF) and cleaned out my MAF and IAC. Any ideas?

 

[Pontisteve]

Symptoms seem similar; too low idling for the first minute or two after cold start.

My engine (1998 Limited 4.0L SOHC) is of a different layout though and I can't find the elbow described.

Made sure the air vents I could find are attached properly (you can see the black duct tape on the exits after the MAF) and cleaned out my MAF and IAC. Any ideas?

Photo:

The PCV tube will be a large rubber hose running from one of the valve covers to the intake manifold somewhere. They've talked about it elsewhere on this site, and there's probably pictures in those threads. You can probably test it by spraying a small amount of carb cleaner or brake cleaner near the bends to see if the engine reacts. Follow the hose from the valve cover to the intake.

 

[Hwebster69]

First off this has been a great thread and has saved me a heap of cash but here is what I'm experiencing. rough idle, bought cleaner for mass air flow and cleaned it twice, after cleaning the old IAC twice as well I decided to replace it. Replaced the 90 degree rubber elbow as described so it's new. Took the ERG off inspected and it ok but I cleaned it as well. Put new plugs and boots in. Changed air filter. I've run the UNLIT propane around every hose I could find with no motor idle increase at all. I just feel like ice tried everything and all that's left is the MAF to try and replace.
Codes I was getting we're the MAF and IAC. The CEL has come back on and unfortunately it's going to be a week before I can get back and get the MAF installed. Has anyone had any luck with aftermarket MAF units? The original equipment MAF is running $188 and I know that's cheap compared to taking the car to the dealership. Just looking for opinions and experience.

The Motor is in my 02 Eddie Bauer explorer with the 4.6L V8.

Motor ran fine for about 60 miles and now has started to revert back to the issue of a rough idle and while driving it has a tendency to shutter or stall while at speed.

What it also seems to be doing is running very rich at idle and at speed. At idle you can smell the extra fuel coming out the exhaust.

My last ditch effort will be to replace the mass air flow unit and see if that corrects the problem. What my question is does the mass air flow unit really have that large of an affection on the motor at idle? it just baffles me how the motor can go from running so smooth to so rough at both idle and at speed. At highway speeds i would also describe the acceleration as mushy and at other times fine. Very weird.

Any other things I should be looking at besides the Mas air flow unit. How about O2 sensors?

Thanks again

Harry

Again thanks for the insight this thread has provided.