Taking in my car for a defective gas cap is very annoying. It takes time and I got better things to do than change my gas cap. The dealer tells me Its a ongoing problem with all chevy's. I told them it is my 3rd time changing the cap..They said "maybe it is customer's who are rough with the cap and that they rush and put the cap on too tight and maybe they put it on wrong." I told them since it is my third time the engine light came on for my gas cap maybe they should hold a class on how to screw on a gas cap since I might be rough on putting on my gas cap........I am taking the car in again march 2007 for the same problem.... Their answer to the problem is bring your car in and we will change the cap. I am going to contact the customer service. to see if I can get an extended warranty on the gas cap