Hello I have a 1997 Cadillac Deville Concours and I just recently had my O2 sensor replaced. Before this I had a tune up and the guy reset the light and it coming back on so I had the O2 sensor replaced. I have posted here about my a gasoline smell in my car and it turns out when I checked the fuel rail that I had put on that it is leaking. I am going back to the dealership on Monday to get that taken car of, but I was wondering would that leak cause that light to come on. If this is not the problem then what would cause that light not to want to stay shut off?