I have taken my vehicle which has 67,000 miles on it, twice to a certified Saturn location for the "service the enjine" light on. The first time they did a diagnoic test and said I didn't have my gas cap on tight enough. The second time they told me the gas cap would have to be replaced and they did, but as I drove home I noticed a strange vibaration as I was going up a hill that had not been there before, almost like it wasn't getting enough gas. Now I am taking it back again (the light is on again) and I don't think they have a clue what is wrong with it. Anyone else have this problem?