I have a 2007 Chevy 3500 4x4 4dr with a Bradford Built flatbed, use it for hauling a horse trailer and at 30, 000 miles had alot of problems with the "Reduced Power" light coming on (reduced power means 25 mph regardless of where you are) after 6 trips to the dealership no recall was done and according to GM Service Techs an after market air intake would fix the problem...it did but had to pay for it out of my pocket!!!
At 84, 000 miles I started to blow black smoke on acceleration and going up hills, truck has been in the shop 3 times in the past 5 weeks... first time they reprogrammed computer and added updates, 2nd time they changed turbo sensor, this third time they changed EGR valve, still same problem. I went from 12mpg to 6 mpg, truck is going back to the shop for the 4th and last time for new injectors (covered under warranty as I verified with GM Powertrain Warranty this morning) if not fixed this time I will get the Lawyers involved. I understand that things break but I also understand that it is GM responsibility to fix it and fix it correctly. I have been a die hard Chevy guy for 20 years (this is my 4th Chevy truck in the past 20 years) I can also promise you it will be my LAST one.

I have a 2003 Chevrolet 2500 HD pickup with the 6.6 Duramax diesel engine. At 35, 000 mi the fuel injectors went bad and they were replaced under warrenty. The injectors carry a 7yr 200, 000 mi warrenty. At 81, 000 and 6 yrs, only 46, 000 from the first replacement, the injectors went bad again. I took the vehicle to a dealer and they charged me $190 to inspect and tell me what was wrong. They stated my injectors were bad but not covered under the warrenty??? They stated that cleaning the injectors needed to be done. I paid the $300 to clean the injectors, but the injectors were still bad. The dealer stated that GM would not replace the injectors under warrenty because they were not bad, but the truck still wasn't running correct. I ask if my injectors were bad and they stated yes but not under warrenty?? They said it would cost $5000 to fix, I said NO! I came home and called GM customer care, issues with warrenty, and told them my story. They in there wisdom called the dealer to find out the story and only took there side. They told me that they would not cover my bad injectors because the dealer said so, no second opinion or anything, just no. I still don't understand why they won't replace my injectors but are giving fair warning to everyone else out there that this has to do with $$ and if you are thinking about a new vehicle it would be wise to get away from any GM product as they are sure to go under with the way they treat there customers. I for one am switching to Ford and will never purchase a GM product again.

I have 2003 GMC 2500 HD Duramax and have the same issue. All 8 Injectors were replaced at 114 k. My truck has 162 k and now dealership says 6 injectors are bad. Just started the process seems like they don't want to pay for the repair.Will give updates
Thanks Kevin (If there is a lawsuit I'm on the bandwagon)