I bought a new 07 Saturday, a left over on a lot. I was really happy until about 4pm today. 341 miles on the clock and the check engine light is on. There is a sticker under the hood that says the truck was up dated on 6/14/08 and has the numbers 55351115AT on it. Any idea why this light is on, the truck runs fine otherwise. Thanks. ( It is a 6. 7, 3500, Mega Cab 4x4. )