Misfire in all right side cylinders/bad 02 sensors.

[PlotxHead4L]

hey guys, first of, hello. Been lurking the forum since I purchased the vehicle over a year ago. Finally have something I need to ask, if what I have going on can even be helped at this point. My apologies for my loose terminology as I'm all in the process of learning all of this.

So as I stated above, I have owned the vehicle for about a year now, bought at 168K miles, ran alright, previous owner was my step-father, and he took rather decent care of it (his words, not mine) just after purchasing it, I had replaced the catalytic converter as it threw up codes during my initial inspection after purchasing it(thankfully my step father paid for that one) and I believe some down-pipe was replaced with it. Normal stuff. From after that point on, the Service Engine Soon came on in maybe March or April, same mechanic who did my cat I took it to him for a brake job and noticed the SES light was on, and just cleared it without even bothering to actually look at the codes saying "if it comes back on within 50 miles, then I'll take another look" and it didn't. It ran "normally" for months, maybe late August, SES comes back on, and as my A/C and heat was dying on me, I took it back to the same guy, cleared out the codes, saying again he wasn't gonna chase it down unless the light returned within 50 miles. Which it did not. Fast forward to about a month ago. My inspection is coming up, and i'm having issues with the starter. So two birds with one stone here. my light was on, figuring it had something to due with my starter. He tells me its a exhaust leak that caused it, clears the codes and again, same thing. He can't pass my inspection unless I put miles on it and see what happens. I let it slip for two weeks, then the holidays come up, so this brings me up to about a week ago. I notice after sitting idle for roughly 5-10 minutes my entire cabin was vibrating. I turn it off, and go back into work. When I turned it back on to drive home, I noticed that same heavy vibration during idle, also my engine was significantly louder, and the SES had returned. I had to do some more driving later on that same evening, and noticed the smell of sulfur/rotten eggs, as well has stuttering mainly when changing gears from park to drive or from drive to reverse. The vibration/knocking seems to almost completely subside when I accelerate, but I also notice mild power loss while accelerating. So I finally am able to get it into my mechanic this last week, where at first he tells me, yea its fine, it had 12 or 13 codes stored, and yea the engines a little loud but it shouldn't be a big deal. Just gonna test drive it and give me a new sticker. Calls me back today saying that every time he clears a code, then turned the truck on, they'd immediately return, 6 in total. I should have specifically written them down, however the description from what he told me, and what auto zone told me, was misfire in cylinders 2, 4, and 6 (all right side) and bad oxygen sensor code from each one. Also worth mentioning is that the day after I first noticed the vibration, I attempted to show my step-father what I noticed, and the SES was flashing at me this time. So I immediately turned it back off, let it sit for two days, and now the lights just back to constant.


Sorry for the huge wall of text there. I was just hoping to give enough context to hopefully get a good diagnosis or even just a solid opinion on my options here. My mechanic, without even deciding to pop the hood said that the engine was probably beyond repair, and even more inconveniently because of the SES he couldn't give me a sticker either. Fortunately he didn't charge me for anything at all as he didn't see that as fair. He told me I could go the route of doing basically a tune up, and seeing if that helps at all, or just driving it till she dies. Got it back from, took it over autozone to get the specific codes, and the manager there basically told me the same thing at first, then began to try to sell me on the idea that it MIGHT be repairable, but in the same conversation told me "If i was that mechanic, I would sold you those repairs, and see if it worked rather the other way around" so. This is my first vehicle. I love it. I'd hate to part with it. I'm willing to do what I can to keep her alive (at least till income tax time, then maybe I'll just find me another beater ) like I said. My mechanic didn't even think it was worth the time of trying to figure out more specifically what was wrong with it, if you guys have ANY ideas. that'd be much appreciated

 

[ptf18]

Um...... IMHO... I'd a found a "new" mechanic. "yeah its a little loud but shouldn't be a big deal".... Um.... Then he should of given you an inspection sticker.

What year S/T do you have? Also how is it equipt?

We both know (or should) that when ANY of the dash warning lights illuminate it warrants more than "clearing them and seeing if they return". Although I have to admit... I've done that.....and after they return I find out the real cause.

Anyways..... Hopefully some of the other long term members will give you some input about your situation. Here's mine.

What specific reason did you replace the Cat for? They'll last forever if properly used and taken care of.

What specific codes have you got? I "assume" the "bad O2 sensor" is the pre-cat #2. What about the post cat? I would think that if the R/H bank of cylinders are causing problems that the #2 O2 Sensor would be inundated with "bad exhaust" (overly rich????) and perhaps indicating that its "bad". I assume you do not have access to a OBD II diagnostic tool. If not, go to 2 or 3 different retail auto shops and let them give you the codes. Perhaps better would be to spend the bucks and go right to a FORD dealer..

The 4.0l V6 engine is a OK engine. A major fault with it was the timing chain design. If you have perused thru this Forum you'll have found (and read) that. Are you hearing the well known clacking noise at start-up?

How many miles are currently on the engine and how many miles have past since a THROUGH tune up was accomplished? And I mean THROUGH....not just oh the plugs were changed...um...last year. That also includes ALL the fluids/filters.

You noticing coolant levels dropping?

Any fluid leaks and I mean any not just open the hood an gaze... a THROUGH over, under, sideways, down look?

Do that with ALL the wiring also.

Did the previous owner keep THROUGH records of the vehicle? If so do you have them?

One of the very 1st things I would do though....and its just me.... would be to THOROUGHLY clean the engine and under carriage. Again I mean hand scrubbing, brushing, solvent using type of a cleaning not just going to the car wash and squirting soap/water on everything. Perhaps you have already done this and if so disregard.

Come back with more info and what you have found. We'll see what we can do.

 

[koda2000]

1. Catalytic converters don't just wear out or go bad. They are ruined by oil or too much un-burned fuel getting into them. Sounds like your O2 sensors may have started your issues and are still contributing to them. The heated O2 sensors used in your vehicles are due to be replaced at around 120,000 miles.

2. Cylinders 2, 4 and 6 are NOT on the same side. Cyl 2 is on the passenger side and cyl's 4 and 6 are on the driver's side.

3. What does SES stand for? I've never heard of it. SRS? CEL? Service Engine Soon?

4. When the check engine light (CEL) comes on there is a problem (usually sensor related). The codes stored in the PCM give you a clue as to which sensor(s) to look at. Codes should not be cleared without determining what the issue is and fixing it. It is illegal for a mechanic to clear codes w/out fixing the problem. Besides, clearing the codes accomplishes nothing. They will just come back. Clearing the codes w/out fixing the problem and telling you "it's no big deal" is just stupid and issuing a passed emissions sticker on a vehicle that has emissions problems is also illegal. Your so-called mechanic can be heavily fined.

3. You need to find yourself a real mechanic and NEVER go back to that idiot.

As far as what may be wrong with your engine, without the ODB II codes there's no where to even start looking. I will tell you that often multiple codes are generated buy a single problem.

Your multiple misfires are probably being caused by multiple spark plugs being fouled. This could be due to bad O2 sensors, but if this is the case you catalytic converter is also being ruined and there's no way you're going to pass emissions w/out fixing the problem(s). When's the last time you had a tune up?

 

[PlotxHead4L]

Um...... IMHO... I'd a found a "new" mechanic. "yeah its a little loud but shouldn't be a big deal".... Um.... Then he should of given you an inspection sticker.

What year S/T do you have? Also how is it equipt?

We both know (or should) that when ANY of the dash warning lights illuminate it warrants more than "clearing them and seeing if they return". Although I have to admit... I've done that.....and after they return I find out the real cause.

Anyways..... Hopefully some of the other long term members will give you some input about your situation. Here's mine.

What specific reason did you replace the Cat for? They'll last forever if properly used and taken care of.

What specific codes have you got? I "assume" the "bad O2 sensor" is the pre-cat #2. What about the post cat? I would think that if the R/H bank of cylinders are causing problems that the #2 O2 Sensor would be inundated with "bad exhaust" (overly rich????) and perhaps indicating that its "bad". I assume you do not have access to a OBD II diagnostic tool. If not, go to 2 or 3 different retail auto shops and let them give you the codes. Perhaps better would be to spend the bucks and go right to a FORD dealer..

The 4.0l V6 engine is a OK engine. A major fault with it was the timing chain design. If you have perused thru this Forum you'll have found (and read) that. Are you hearing the well known clacking noise at start-up?

How many miles are currently on the engine and how many miles have past since a THROUGH tune up was accomplished? And I mean THROUGH....not just oh the plugs were changed...um...last year. That also includes ALL the fluids/filters.

You noticing coolant levels dropping?

Any fluid leaks and I mean any not just open the hood an gaze... a THROUGH over, under, sideways, down look?

Do that with ALL the wiring also.

Did the previous owner keep THROUGH records of the vehicle? If so do you have them?

One of the very 1st things I would do though....and its just me.... would be to THOROUGHLY clean the engine and under carriage. Again I mean hand scrubbing, brushing, solvent using type of a cleaning not just going to the car wash and squirting soap/water on everything. Perhaps you have already done this and if so disregard.

Come back with more info and what you have found. We'll see what we can do.

Hello, first of all, thank you for taking the time to help me out here. I'll try to answer these things chronologically. As far as it goes with this mechanic, I don't think he's a bad guy, perhaps lazy as he might have known what a pain in the ass the SOHC is, but ultimately he and I both had the agreement to keep it running as cheap as possible, so its fairly both of our faults to that end.
First things first, and I do apologize greatly, but....I just have a XLS LOL I didn't realize there was a more standard forum for the plainer models till after I posted this, so if a moderator wants to move this thread I'd understand. However everything else you asked is still relevant. She's a standard 2002 XLS. The reason I wasn't given a inspection sticker is I live in the LOVELY state of New York and without even guessing what was wrong, correctly guessed I wouldn't be able to pass a emissions test. So I suppose that makes sense. Here is the list of engine codes I got from a reading from Autozone about 3 days ago. P0300(Random Misfire Detected) P0301-303(Cylinder 1-3 misfire detected) P1132(Lack of H02S11 Switches - Sensor Indicates Too Rich) P0174 System Too Lean (Bank 2) and finally P1151/P1152 System Indicates Lean/Rich. The lean/rich codes are actually new as previously my engine had only been giving off misfire codes. The suggested repair by Autozone(trust me, I didn't take it too seriously) was that my Mass Air Flow Sensor was shot, and I tested this myself by running the engine and disconnecting the MAF sensor, where there should have been a change of idle, or a complete shutoff, and no change. Indicating to me that the sensor was indeed shot. I will mention that since I have done this, about 3 days ago, and putting a few miles on it, that the loud knocking and idle vibration has all but subsided. It still returns usually when coming to a dead stop while driving as well as changing actual gears like from Drive to Park, I notice my RPMS just plummet.

To your more specific questions, the cat was replaced just before/technically during the process of me buying it, about a year ago. The reason why is kind of a funny story, but basically while that same mechanic was doing his road test my check gauge light came on (had low gas) so he had to take it back and rehook it into the computer, and I guess I was throwing too much emission. The previous owner for at least the last 4 years was my stepfather, and he was already replacing the exhaust as it was. It was kinda a violent storm that lead to it being required to be replaced. The last time it was actually tuned up and I don't have the literal date but was well over 3 years ago. Like the summer it was bought from the other owner we did all that kind of work on it, then just procrastinated it, and yes you are correct when saying I have probably read about the dreaded timing chain issue as well as that death rattle. It does make that turnover noise for like half a second before the engine kicks on, as apposed to it being instant, but I have chalked it up it being cold. No fluid leaks from the inspection I did the other day was I was fiddling around with the MAF sensor, was letting it run for a good 20 minutes, I did notice dripping from the exhaust, but from what I could smell it was just water. Coolant level seems to be stable, but I just put some in maybe two months ago, if that. Like I mentioned previously, the knocking noise and hard idle seemed to have been relieved by simply just unplugging my MAF sensor and plugging it back in. My next step is to actually clean that, I just didn't have the torque screw bit to take out JUST the sensor, I have no desire or reason to completely remove the air intake just for that little sensor. It does lack a bit of its power when accelerating, but honestly nothing to terrible. Its mainly from taking off from deadstops. Even under load on a hill it doesn't seem to be affected too much. She has 172,000 miles currently, and I believe last fluid change was at 169,000. Not too long ago. Hopefully I could shed some light, and thank you already!

 

[PlotxHead4L]

1. Catalytic converters don't just wear out or go bad. They are ruined by oil or too much un-burned fuel getting into them. Sounds like your O2 sensors may have started your issues and are still contributing to them. The heated O2 sensors used in your vehicles are due to be replaced at around 120,000 miles.

2. Cylinders 2, 4 and 6 are NOT on the same side. Cyl 2 is on the passenger side and cyl's 4 and 6 are on the driver's side.

3. What does SES stand for? I've never heard of it. SRS? CEL? Service Engine Soon?

4. When the check engine light (CEL) comes on there is a problem (usually sensor related). The codes stored in the PCM give you a clue as to which sensor(s) to look at. Codes should not be cleared without determining what the issue is and fixing it. It is illegal for a mechanic to clear codes w/out fixing the problem. Besides, clearing the codes accomplishes nothing. They will just come back. Clearing the codes w/out fixing the problem and telling you "it's no big deal" is just stupid and issuing a passed emissions sticker on a vehicle that has emissions problems is also illegal. Your so-called mechanic can be heavily fined.

3. You need to find yourself a real mechanic and NEVER go back to that idiot.

As far as what may be wrong with your engine, without the ODB II codes there's no where to even start looking. I will tell you that often multiple codes are generated buy a single problem.

Your multiple misfires are probably being caused by multiple spark plugs being fouled. This could be due to bad O2 sensors, but if this is the case you catalytic converter is also being ruined and there's no way you're going to pass emissions w.out fixing the problem(s). When's the last time you had a tune up?

I answered a few of these in a reply that just came in from someone else. I know you're trying to help someone who clearly doesn't know a whole lot about the entire situation, but most of what you said is common sense/things I already knew/stated. I know SES isn't a common abbreviation for the Service Engine Soon light, but I did write it out completely in my original post.......As for what cylinders were misfiring this was me going off my frazzled memory after being told my 3,000 dollar engine is failing my 300 dollar truck, but its actually 1,2, and 3 (P0301-303) as well as P1151 and P1152 system too rich and system too lean.

We're both aware of the fact its illegal to put on inspection sticker if it didn't actually pass..

 

[ptf18]

PlotxHead4L. Um.... If I owned your S/T I'd start with a through tune-up. I (only) use Ford/Motorcraft parts. YMMV.

Breaking it down by systems. 1 ) Fuel System. chg the fuel filter. 2) Air System. chg the Air Filter, clean out the airbox 1st. Using the correct solvent clean the MAF and IAC. Look inside your intake manifold. More than likely you will see a "pool" of oil sitting in it, clean that oil out. Check that the PVC system rubber elbow is in EXCELLENT condition as it is known to rot out, chg the PCV Valve AND Grommet. 3) Engine Lube Sys. chg OIL and Filter USE TOP QUALITY STUFF 4) Coolant System. Drain the ENTIRE system...not just the radiator. Remove the reservoir and clean the interior out. USE a top quality coolant system cleaner thoroughly flush the cleaner out after using the cleaner. Reservice the coolant system with TOP QUALITY anti-freeze mixed per Ford recommendations. 5) Replace the spark plugs and wires.

This is JUST the ENGINE and the cost.... couple hundred bucks TOPS.

KODA2000 might toss in a couple other items to inspect/clean/replace.

Doing all this will give YOU a starting point to get your S/T up and running.

Oh... and start a detailed log book of your work,parts and p/n's

Pull the battery out, THROUGHLY clean the posts and cable ends. Also clean out where it sits in the S/T. Baking soda/water on the tray area then rinse well and dry. When you reinstalled secure the terminals properly and apply a protectant.

Once you get the "tune up" accomplished Go to a "reputable" shop/parts dealer and get them to read any Codes.

 

[boominXplorer]

Check your compression. If your off on one side of the engine vs the other than you probably have timing chain issues. The passenger side is the common problem side (cyl 1-3)

 

[PlotxHead4L]

Check your compression. If your off on one side of the engine vs the other than you probably have timing chain issues. The passenger side is the common problem side (cyl 1-3)

How can one perform this relatively cheaply on their own? a quick google shows most shops typically ask for 80 bucks to do it.

 

[Tech By Trade]

Up here princess auto will run you 40 bucks for a tester. Harbor freight is probably ballpark down there.

 

[meganmc]

How can one perform this relatively cheaply on their own? a quick google shows most shops typically ask for 80 bucks to do it.

**** What ever happened with it???? ****

I have an eerily familiar situation happening currently with my 02 Explorer sport 4WD 4.0L 6 cylinders.
Only 2 codes misfires on cylinder 1&5 with flashing CEL. I unlike this person have not continued to drive it. Once I saw flashing it got towed to shop. I have 75k miles on it and I have taken very good care of this puppy since I bought it back in 2014 with 17k miles from an old man who didn't drive it much. He stored it in his climate controlled garage at home, maintained services and occasionally he drove it to keep fluids running through it from 2002-2014.
Interior still had that new car smell when I bought it from him. It was (still is) incredible. I never had a tune up done but fluids have been flushed and oil changed regularly. I had a vacuum hose disconnect somehow about 8 months ago that went unseen for a few weeks. But other than that she was good.

After the misfiring codes with flashing light I had it towed to a (new to me)shop. I asked them to replace the wires coil pack and plugs initially. Mechanic was kind of a mess like this other one sounds lazy and all. After a week or so he called me saying it needs a new PCM. He said "well without taking the truck apart, I inspected the wires, and they seem fine so I'm thinking it's def a bad driver in the PCM." So he ordered one a couple more weeks ago by, he gets it in and installs it, programs it and he said, "it fixed cylinder 1 but cylinder 5 has no compression or very little at times."

I asked if 5 had compression before the PCM switch? He said he didn't do compression test before because it wasn't firing at all

Now I'm no mechanic but i thought that was one of the steps in a standard diagnostics for this type of issue. Before assuming to know anything.
So now he says it's possibly one of too many things that involve removing the cover from the engine that it's gonna cost me too much. And it's not guaranteed to point us to the issue and while that's all apart it's best to replace the timing belt and chain while we are in there. And he's talking about the crank and camshaft being his next guess to why there's no compression. I asked him if he checked all the sensors and their positions, all the valves and idk maybe the fuel injector? I also asked if the PCM actually did anything by replacing it? Was that necessary?
He's convinced it got cyl 1 firing. I think if anything he maybe only needed to reprogram it and that changing out my coil pack is actually what got it firing not the new pcm. Or the wiring is failing and moving them around had somehow got them working temporarily.
Regardless I know this truck has a lot more life in this engine. I haven't abused her. I have the same knocking and sulfur smell as mentioned above.
The timeline is freaky cuz it's exactly the same as the person above mentioned. Vacuum hose leak began in spring. Check engine light on then. Off after finding that issue. Replaced a hose connector and it wasn't the right type so it was concaving on itself. That set off the engine light again but fixed and that got replaced when we got an oil change right before this issue. That's when jiffy lube mechanic asked me about the spark plugs ever being changed. I said no and two weeks later, a week before Xmas the CEL flashing, knocking, sputtering and loss of power all happened out of nowhere. Fast forward to today, February 10th and my explorer is still in the same shop with this brilliant mechanic. I just don't know what to do.

Any advice?

 

[boominXplorer]

After the misfiring codes with flashing light I had it towed to a (new to me)shop. I asked them to replace the wires coil pack and plugs initially. Mechanic was kind of a mess like this other one sounds lazy and all. After a week or so he called me saying it needs a new PCM. He said "well without taking the truck apart, I inspected the wires, and they seem fine so I'm thinking it's def a bad driver in the PCM." So he ordered one a couple more weeks ago by, he gets it in and installs it, programs it and he said, "it fixed cylinder 1 but cylinder 5 has no compression or very little at times."

Any advice?

First place I'd look is spark plugs, plug wires and coil. 1 & 5 share the same coil leg so it points me towards that stuff. It can be a bad coil or a shorting plug wire on either of those cylinders. I'd confirm new parts were actually installed.