Mine is an '04 and if you have one you may not be aware of this but........mine began running like complete crap two days ago. Went into limp mode and would barely do 20mph. Once warmed up I could build boost and go but whenever going it had to be 80% throttle minimum or it would be gutless. Got it back from the dealer today (who better then to work on the engine) and it was wiring with the injectors. The wires have 110 volts running through them and with vibration they tend to scar and arc. One enjector clip was actually melted. GM has a bulletin out about this and will eventually happen again. Its not too big of a deal but can be a pain in the a**. Cost me $0 and the truck is back up and running. The diesel tech........he knows more then anybody I've ever met about any diesel vehicle, certified on anything and everything.......said the 4500 I have was the strongest he'd ever driven and was fast in comparison to others. Guess it goes to show take care of your stuff and it will take care of you. Just a little FYI.