LS4 Performance - CEL troubles

So alil back story in-case this has anything to do with the current issue.

Couple days back I had a new catless DP installed cause I broke the flex pipe. My old catless DP was stock size with no cat. My new one is 3inch (with a 02 bung) all the way back till where the res used to be and then goes back to stock size with aftermarket mufflers. The car pulls a lot better up top now :)

So a couple days after I had all this done I went to turn on my car via command start and the cars fog lights just kept blinking at me. So no biggie I walk up and turn it on manually. Then about half way to work I get a a CEL. So I stop off at a friends and scan it with a OBDII reader and no codes are found. So at work I disco the battery and the CEL goes away.

Half way home the CEL turns back on. Command start still not working.

Drove down to my uncles shop and hooked it up to a tech2 and he couldn't find any codes....

sorry for being long winded and thnks if anyone has a clue wth is going on haha!

setting the code will kill the remote start feature. Disconnecting the battery likely resets the light, but the code probably is tied to a few cycles of restarts. (ex: it might need 3 starts and a run to normal temp. without seeing the trouble for the code to reset)

Have you had the rear O2 sensor tuned out of the system?

setting the code will kill the remote start feature. Disconnecting the battery likely resets the light, but the code probably is tied to a few cycles of restarts. (ex: it might need 3 starts and a run to normal temp. without seeing the trouble for the code to reset)

Have you had the rear O2 sensor tuned out of the system?

Looks like we have a winner.

I got it tuned by a local trifecta dealer. Ive already been in contact and he says the rear 02 has been turned off.

You are right the CEL did appear after a few starts and a long trip to my parents place.

I just pulled the negative terminal again and hoping it fixes the issue for a bit.

The trifecta dealer will take a look when hes back from saskatchewan.

Ive never seen a CEL with no thrown code lol