I had my check engine light come on the other day, so i had the codes pulled and it came up as a p1131 code. I figured out that it could be many things. My only real question is that the other day the light went off. Last time i took my car in it did the same thing, the guy told me the car stores the code and there could still be a problem. Well do i really need to take my car in if the light went off? The car runs fine, so i dont want to have to pay for nothing.