Well I haven't technically tested it to see what the exact code is. I was just figuring that that was the problem since right after it was installed the cel showed. And I have talked to people around here that have done the IM on their gsrs before and they said they had the same deal. Oh and I have tried to go and see what code it is showing but for some reason the little port thing or w/e where you plug into to check and see what code it is throwing does not work on my car. Autozone told me this? I have no clue why it would not work.