After all my issue with my ecu, I finally have the truck running great. How ever. A new issues has arrived. I had a code for P0420. I believe that means I need a new cat, But this code started after I unplugged the rear o2 senor and drove the truck. IS there something I could of done by unplugging it to set the code. I tried resting it with no luck.

Can I clean the o2 sensor?

Thanks!!!

 

Theres not really any way to clean 02 sensors that i know of. I had the same problem a couple months ago I tried new 02 sensors without much luck. I finnaly ended up putting 2 new magnaflow cats on and within 100 or so miles the code cleared.

 

This can not be reset. Why did you unplug one 02?
How many miles on your engine, have the 02's ever been changed, what octane gas are you using and have you ever blown the head gasket on bank 1?

 

This can not be reset.

Why did you unplug one 02?
I could not get my ecu to trip any codes, So I unplugged it to attempt to get a code from the ecu. I ended up replacing the ecu and forgetting to plug it in.
Got a cod for it not being plugged in. Fixed it and now this code comes back a week later.
How many miles on your engine, have the 02's ever been changed, what octane gas are you using and have you ever blown the head gasket on bank 1?
119k, Not that I am aware of. I am selling the truck. I only use 91 octane. Had a collant leak on Cylinder 1 so I replaced the head gaskets.

 

All 4 O2's on a DI are the same, so you can swap that O2 with a known "good" one and see if the code moves or comes bad.
The rear O2's do nothing other than tell the ECU if the cats are working or not.
Can you clean them? I have heard of people doing it but I have not so I dont really know the answer.