Probally the gas cap. I'd replace it again. As small of a leak that is needed to cause the CEL, you will have a tough time finding it without a gas test.
My old Sebring had this CEL and it ended up not being the gas cap. Took it to a good shop and they ran the gas test 3 times and couldn't find the leak. I got pissed and just put zip ties on the end of each hose back there and my problem was fixed. Guessing it is because they glue the hoses rather then clamping them. Maybe the glue doesn't last forever.
2003 Corvette Z06 - MGW shifter, Corsa X pipe, Corsa Xtreme exhaust, Texas Speed long tubes w/o cats, PowerStop rotors/pads, Conti DWS tires, C6Z51 F&R sways, C5R headlights, tuned
04 GTO - sold
Last edited by jpalamar; 05-24-2010 at 07:05 AM.