I just got a custom off road pipe put on my car on Tuesday and was expecting the check engine light to come on along with some codes to pop up since I removed my cats. Well, when I got it back it threw no codes and the check engine light never came on. I also tuned my car with the Diablo tuner a few days before. Anyway, the check engine light came on today with no codes. I figure this is normal b/c the cats were remove but why now and with no codes?