The last time we got gas in NJ, the attendant did not close the gas cap properly and the check engine light went on. We have now tightened the gas cap and the light is still on. It appears we have to take the van to the dealer to get it checked up could cost 75 dollars or more. Seems like a steep price for silly mistake of a loose gas cap. The van has about 40,000 miles and any ideas on what the problem could be. I would especially like to know if any of these would still be covered by warranty. Just curious.