My check engine light came on the other day so I took it and had the computer scanned. It came up with code 1516 see dealer. The guy said that it was not a big dseal because if it was a sensor or anything else wrong with the car the the computer would have read the code. So at this point he cleared the computer. Well today on my way home I was driving down the highway so I got on it a little.:winks When I did this the check engine light came on again. I am almost wondering if it is the gas cap because it has not been replaced and when I go to tighten it, it just starts to click and wont really tighten. Would this be my problem or has anyone else had this happen to them.