Thread: Removing rear O2 sensor on 01-newer PCMs -- Things you should know

I have never seen my LTFTs positive. I guess my PCM doesn't have this issue. I need to go back in the PCM and see how I have the codes programmed. I know it doesn't throw the code as it never shows on any reader.

Turning the codes off in the tune only hides the fact that the rear 02 is not present or throwing a code but has no effect on the pcm running the cat diagnostics, you just never see a trouble code simply because it is turned off. This also seems to be hit and miss and there are many guys that have never had this problem while some have had the problem and dont know why or how to fix it.