P0156 problem
 

I keep getting the code P0156 02 sensor bank 2 circuit malfunction. Its been a problem ever since I installed my long tube headers. It was a kit with the y-pipe and cats. I bought the system used. Ive replaced the sensor twice and it works for a few months and then acts up again. Ive alaready replaced the bank one cat for a similar code. Im not sure what to do. I was thinking of getting a tune and have the rear o2 sensors programmed out or getting a o2 sim if I can find one.

If it's for the rear o2 sensor(s) (post cats) then its normal for a long tube installation since the highflow cats don't "clean" the air like OEM cats do.

Do you have the set up to tune a 2004 avalanche?