I'm with you Bluetick.......
I have had a new egr valve, filters cleaned and replaced, new turbo, new pcm, and a flash update every time it is in the shop. 15,000 miles and less than a year old (07.5 4door 4x4). They just towed it out of the yard 5 minutes ago. Truck couldn't get out of its own way. Message flashed once 70% full, twice 80%........100% contact dealer.
I contacted the dealer and then my lawyer.
I tow about 5000lbs 4 days a week and have a red cel on almost continuously. Don't know the codes but the answer is always the same "Got to get er' on the hyway and blow er out". I just got done "blowin er out" driving 90mph for about 70 miles. Next day the cel light was on again. POS.
It's my work truck. No truck, no work. No work=loose clients. I've had enough I think it's time to check out chevy.