My '02 Elantra has given the infamous, "Check Engine" light. Indeed, someone else had gassed up the car and not put the gas cap on right. But after two fills, it still has not gone out.
Experienced the same thing when I rented an '04 Santa Fe. Fuel cap not on right, check engine light came on, but then refused to go out. The service guy at the rental place even believed that once the light goes on, it is on for life.
There must be a re-set button or something. Ideas, anyone?
Tom Wenndt