HELP!!! Codes Galore - Changed Plugs & Coils, PCV, Upper Plenum Gaskets.....still throwing same codes.

[GAJeeperGirl]

So, I've got a 2018 JLU Sahara 3.6. It has 102k, knew I needed to do maintenance on it, but got a CEL & stop/start before I was able to. Got a P0174, P0300, C3403, P0301 and P02098. Changed the coils, plugs, pcv valve and upper plenum gasket while in there. Thought I would be fine. NOPE! Drove it around everything seemed fine, husband drove it the next morning for a 12 mile round trip and accelerated to get in passing lane and stop/start came on again. codes are now: P0174(current), C3403, P0157, P0300, P2098(pending) and greyed out C1001, C1020. Realized he had not tightened the upper bolts on the EGR pipe. Cleared faults. Drove again. Codes again: codes are now: P0174(current), C3403, P0157, P2098(pending) and greyed out C1001, C1020 and P0300. Unplugged and plugged something to make sure it was connected. Cranked it up sounded and drove fine...I did several harder accelerations trying to get it to fault. NOTHING!! Thought I was in the clear. Went for another drive later and got same CEL & S/S....codes are now: P0174, C3403, P0301, P0300(current), P2098, P0157(pending) and greyed out B3001, B3020. Went and did a fuel trim test just now....hasn't been messed with in two days, except to move it around the yard and out of the way.
One was at idle (1000rpm): LTFT1 1.56, LTFT2 32.81, STFT1 0.00, STFT2 19.53 These were are 2500RPM: LTFT1 0.00, LTFT2 32.81, STFT1 -3.12, STFT2 25.00. Also the F/TB2S1 read 19.53 at idle and 25.00 at 2500 rpm. Is it my bank 2 upstream o2 sensor?
I am so over this Jeep. What is going on??? Please help!!!! TIA!

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[Stan B]

Sounds like bad O2 sensor(s). Check for an oil leak on passenger side O2. If you replace O2 sensors, reset fuel adaptives.

Also, at that age/miles, ever replaced the batteries?

 

[GAJeeperGirl]

Sounds like bad O2 sensor(s). Check for an oil leak on passenger side O2. If you replace O2 sensors, reset fuel adaptives.

Also, at that age/miles, ever replaced the batteries?

Yes, both early on under warranty in 2021 and the main for a second time a couple years ago. Fuse is pulled and negative off the aux battery. Now it was dead as a door nail, when we started working on it.....or by the time we were finished.....about a month of sitting. So, I do believe a lot of the electrical body codes are coming from that, now that I think about it.
Bank 2 is driver's side, correct? I feel that is where the problem currently. Though to be the good mechanic, all should be replaced. But I'm on a money deficit right now......so.......

 

[mwilk012]

There’s absolutely no need to replace parts that aren’t bad. Diagnose the lean condition, that’s the primary failure here. The entire bank will be misfiring. The question is why. No work was done leading up to the first failure, was there? No mice damage?

It’s less common but definitely put eyes on the left upstream O2 and if you can get voltage readings or even better a graph of B2S1 readings at idle and compare with B2S2.

 

[GAJeeperGirl]

There’s absolutely no need to replace parts that aren’t bad. Diagnose the lean condition, that’s the primary failure here. The entire bank will be misfiring. The question is why. No work was done leading up to the first failure, was there? No mice damage?

It’s less common but definitely put eyes on the left upstream O2 and if you can get voltage readings or even better a graph of B2S1 readings at idle and compare with B2S2.

It doesn't sit long enough for mice damage......it's my every day driver. And nothing was done to it other than oil/air filter changes under the hood. I just knew that once I hit 100k, I needed to change plugs (which were bad looking when removed) and the few other things since I was there and the driver's side is such a pain.

 

[alphawolff]

It doesn't sit long enough for mice damage......it's my every day driver. And nothing was done to it other than oil/air filter changes under the hood. I just knew that once I hit 100k, I needed to change plugs (which were bad looking when removed) and the few other things since I was there and the driver's side is such a pain.

stop thinking about it and just go look at the damn rear o2 sensors and see if they're covered in oil. it's a common issue; i had one just yesterday.

 

[Islander Man]

It may be some of the “new” parts you just installed are bad. I’ve seen instances where even though it is a new part it still may be defective. I usually try to go with OEM when it comes to replacing such things as coils.

 

[GAJeeperGirl]

It may be some of the “new” parts you just installed are bad. I’ve seen instances where even though it is a new part it still may be defective. I usually try to go with OEM when it comes to replacing such things as coils.

Went back with MOPAR. But in the end....it's all junk to some extent.

 

[DaltonGang]

stop thinking about it and just go look at the damn rear o2 sensors and see if they're covered in oil. it's a common issue; i had one just yesterday.

That's it you mean person you. Now she will never check the O2 sensors. You've been Ghosted.

 

[DaltonGang]

So, I've got a 2018 JLU Sahara 3.6. It has 102k, knew I needed to do maintenance on it, but got a CEL & stop/start before I was able to. Got a P0174, P0300, C3403, P0301 and P02098. Changed the coils, plugs, pcv valve and upper plenum gasket while in there. Thought I would be fine. NOPE! Drove it around everything seemed fine, husband drove it the next morning for a 12 mile round trip and accelerated to get in passing lane and stop/start came on again. codes are now: P0174(current), C3403, P0157, P0300, P2098(pending) and greyed out C1001, C1020. Realized he had not tightened the upper bolts on the EGR pipe. Cleared faults. Drove again. Codes again: codes are now: P0174(current), C3403, P0157, P2098(pending) and greyed out C1001, C1020 and P0300. Unplugged and plugged something to make sure it was connected. Cranked it up sounded and drove fine...I did several harder accelerations trying to get it to fault. NOTHING!! Thought I was in the clear. Went for another drive later and got same CEL & S/S....codes are now: P0174, C3403, P0301, P0300(current), P2098, P0157(pending) and greyed out B3001, B3020. Went and did a fuel trim test just now....hasn't been messed with in two days, except to move it around the yard and out of the way.
One was at idle (1000rpm): LTFT1 1.56, LTFT2 32.81, STFT1 0.00, STFT2 19.53 These were are 2500RPM: LTFT1 0.00, LTFT2 32.81, STFT1 -3.12, STFT2 25.00. Also the F/TB2S1 read 19.53 at idle and 25.00 at 2500 rpm. Is it my bank 2 upstream o2 sensor?
I am so over this Jeep. What is going on??? Please help!!!! TIA!

I see you are pretty well versed in the Jeep Thing issues, except the O2 sensors. They can play havoc on things. They are easy to check. Just use a flashlight to see if there is a trickle of oil on any of them.

 

[bmpcamry09]

Don’t worry about the U codes, every Stellantis product on the road has a U code or a lost comm code.

The data is telling all. Ignore the codes and attack the problem. Bank 2 isn’t happy. Most likely rear O2 sensor. But if not you need to focus on air/fuel things on that side.

 

[GAJeeperGirl]

I see you are pretty well versed in the Jeep Thing issues, except the O2 sensors. They can play havoc on things. They are easy to check. Just use a flashlight to see if there is a trickle of oil on any of them.

I am going to look at the O2 sensors, but it could just be one has gone out... Life cycle being 60-100k and I'm at 102k. Thank you!

 

[mwilk012]

I am going to look at the O2 sensors, but it could just be one has gone out... Life cycle being 60-100k and I'm at 102k. Thank you!

They don’t typically just wear out , they get destroyed by external factors. Oil leaks, usually. Open your hood, lay on the ground, take a look around. All of this takes less time than making a ham sandwich.

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