I have replaced the gas cap 5 times on my 2007 Sky. Check engine light comes on I go to the dealer and they charge about $78. After the 4th time they wanted to see me take the cap off and on. I am not doing it wrong. Mechanic said the rough ride of this car can juggle it loose. But loos the deal? I see I not alone. Still a pain. You never know for sure what it may be as every time it has been the gas cap.