A few days before thanksgiving, my check engine light came on and stayed on. A quick check to the owners manual told me low gas could be a problem, sure enough, that fixed it. Fast forward to last thursday, I filled up. Then Friday my CEL comes on again, can't be low gas this time... I unscrewed and tightened the gas cap (like the manual says), the car wouldn't run if there was water in the gas - but the car is running just fine. Any clues to what this could be? And to you who like make it obviously clear that the search function is there for a reason, right now it's down. Any help would be appreciated. Thanks.