Hey. My 2006 Silverado got light. Went to auto zone scan. It's show




Which exactly it is. O2 sensor? I know that Nelson program my PCM to delete rear o2 cause I ran a catless. It been fine for 2 yrs. now happen can you help me which one

 

It is being triggered through the upstream sensors. I would check to see your MAF is reading correctly, and also check for any vacuum leaks or potential causes of under fueling.

 

What's the code that they got to get that definition? P0171 and P0174? What other conditions are present when that code is active? What are the O2S reading? Etc.

The Autozone printout is more or less designed into getting you to purchase 120 dollars worth of stuff you don't actually need but actually can't return.

 

let me check and will right back to yall

 

P0175 bank 2 too rich*
P0172 bank 1 too rich

Which one I need know that needs to replace front or rear. But Nelson program my PCM cover for rear o2 I think. Pls let me know.

 

Both sides rich like that is most likely a bad mass air flow meter. Try cleaning it with some carburetor cleaner or mass air flow sensor cleaner if you can find it.

There is a chance that a table is not programmed correctly in the tune but I would suspect the MAF before the tune at this point. Oxygen sensors are not likely to be the culprit as they usually fail lean instead of rich.

 

Thought if I clean maf will mess up?

 

No it wont mess it up they sell cleaner just for that at Autozone etc.

 

 

[QUOTE=00ChevyScott;4854273][/QUOTE

Thank you. I will do.