While driving my Auto 03 SE yesterday I noticed my CEL. It was on for the better part of a half hour drive. By the time I returned home it had turned off. It remained off for my drive to work this morning. Since December the power and gas mileage has been very inconsistent (intermittent lag between 4-6K). I have taken the car to dealer to have it checked out before, but they were unable to find a problem. From what I have read in the fifth gen forum it sounds like the problem my be my MAF or my Knock Sensor. Do any of you have any ideas? If I take it to a dealer will it display a code even though the light has turned off.

 

The code should still be available unless the battery has been disconnected. Unless you're under warranty still I'd take it someplace like Autozone to get the code read for free instead of the dealer (my dealer charges $105 to reead the code). Let us know what the problem turned out to be. Others have had this problem too.