I popped my first CEL yesterday. It turned out to be the P2000 code. So they went ahead and reflashed it with the new AX Code and man, what a difference. I drove it about a hundred miles this morning and averaged about three miles to the gallon better than I have since I bought the truck. It also seems to run smoother and have more power. Like was said in an earlier thread, " I am finally proud of my trucks mileage! ". We'll see how she holds up for as far as poppin the CEL.