So I got this code today and went to pepboys to have the code pulled.

Notes:
-I don't have a cat, and have had a CEL fixed (sparkplug nonfoulers) these havent given me an issue for over 6 months or so.
-not sure if it popped up on start up or while driving
-only thing I did from when I know it wasn't there to when I noticed it was 1 quick 2-step and I changed my license lights, everything else was normal granny shifting around town
-idle is fine
-2004 8 with 43,000 miles


I've looked up some posts on here but no one really has a defined answer.

Looking for some guidance as i assume this is a common issue.

 

I also have the antifoulers and the code popped up again a few months ago. I just reset the cel and it hasnt come back on again. Reset the cel and if it comes back on multiple times its possible the actual sensor is bad. If you can, disable it via ecuflash.

 

Clear the light and see if it goes away then you don't have a problem. That code like to come up with different mod if it come back you my need an 02 sensor. You can alway have a tunner remove it

 

Just cleared it, gonna drive around some today and see what happens

 

Just drove around 5 miles and it popped back on, same code. Suggestions?

 

Maybe bad sensor?

 

Okay so what happens, is ill clear the code and drive for as many miles as I want, but as soon as I turn it off then on again, it pops the cel

 

The P0138 is the the heater circuit for the rear O2

The P0420 is the below efficiency code that you'll throw when running no cat.

What I would look at first is the wiring from the rear O2, to the connector and into the cabin. You may find a broken/damaged wire. If not I'd likely replace the rear O2 sensor

 

yeah Im not getting the cat code, that was fixed by the non foulers and the car has already been inspected no problem.

How do I go about getting to the wires from the cabin?

 

Follow the wires from the rear O2 they'll go up into a grommet, from there you can remove seat, and peel back the carpet a bit. You'll now see the wires run to a connector.

 

okay thanks man