O2 sensor codes won't go away even after replacing them

[Tj359]

I have an 06 tj, 4.0, 6 speed. I'm getting the following codes
P0031
P0037
P0051
P0057
I have replaced all 4 O2 sensors, with the proper ntk units, cps, and dual tip platinum plugs. Still have the codes. Any ideas? TIA

 

[Chris]

Either a short in the wiring harness somewhere or your pre-cats are failing.

One of those two I would guess.

 

[Jerry Bransford]

I'm thinking either a bad pre-cat or a bad ECM. Someone else with those exact same four codes even after new NTK O2 sensors too was only able to get rid of them with a replacement computer.

Since I can't quote the post here, this is what it said...

"The problem is hopefully solved; a bad PCM! it was COVERED under federal emissions warranty with 3 months left to go!! I had to get this fixed to pass inspection this month. "

I'd check with www.Wranglerfix.com

 

[L J]

I have an 06 tj, 4.0, 6 speed. I'm getting the following codes
P0031
P0037
P0051
P0057
I have replaced all 4 O2 sensors, with the proper ntk units, cps, and dual tip platinum plugs. Still have the codes. Any ideas? TIA

'06 LJ 4.0 6 speed and I had the same problem (* no drivability issues at all). I replaced the four O2 sensors with NTKs, checked/cleaned the grounds and reset the computer. A retired CDJ mechanic used his DRB to diagnose a failed/failing PCM. I bought a NOS Mopar PCM and he programmed it. Issue resolved and so far so good. This was before @Wranglerfix was up and running.

 

[Wranglerfix]

I have an 06 tj, 4.0, 6 speed. I'm getting the following codes
P0031
P0037
P0051
P0057
I have replaced all 4 O2 sensors, with the proper ntk units, cps, and dual tip platinum plugs. Still have the codes. Any ideas? TIA

It sounds like it could be a pcm issue. Any other symptoms like low idle or completely stalling while driving?

 

[Tj359]

No other symptoms, runs great otherwise. Scan tool says "low voltage" after the codes.

 

[Wranglerfix]

No other symptoms, runs great otherwise. Scan tool says "low voltage" after the codes.

Good morning,

How old is your battery? My tech recommends changing it if it is over a year old, even if it tests good.

If it turns out to be the pcm, I can get one coming to you. If it does not solve your issue, I gladly accept returns.

You can call me if you’d like at 866-888-7710 if you would like to talk over type.

Thanks,

Mark

 

[Tj359]

Mark, I was just about to email you, my question was what if it is not the pcm, is there a way to check it? If you accept returns then that answers my question. I will try a new battery. If not, I will give you a call. Thank you.

 

[Wranglerfix]

Here is a video by @Ozzstar that will show you how to test the pcm.

 

[N6WHZ]

I just went through the same problem as stated. Even replacing all 4 O2 sensors with the correct NHK sensors. I was following a trail that had me thinking it was a ground failure. Long story short, I removed all the PCM connectors and sprayed both sides with a quality electronics contact cleaner and the problem was fixed.
Now I need to replace all the split loom under the hood. The crappy factory split loom has literally disintegrated.

Pat R.
Menifee, CA
05 Jeep Wrangler Sport 4.0l

 

[N6WHZ]

Here are before and after photos. I used good quality electronic contact cleaner and a soft brush to clean away the corrosion on the pins. It required about 3 or 4 cleanings to get them right. If you are getting all 4 O2 sensor heater codes, check this out before you start replacing O2 sensors.
Good Luck