Hello all, I am new to this forum and have a bit of a problem. I have an 02 Chevy 2500HD with the Duramax and my SES (Service engine soon) light will comme on and go off. Usually it is on for a few days then goes out. I feel like my truck has lost some power and when accelerating it seems gutless. During a heavy acceleration it also belches out black smoke. This is my firts diesel truck and it has 56,000 miles on it now. I have not done any mods to the engine or exhaust. I did have a K&N air filter in it. Just put in paper element filter so I can clean the K&N. Any info would be greatly appreciated.

Ditch the K&N, it is known to cause issues. Who's the maintenance schedule been? Regular oil and fuel filter changes? How does the oil look, thin or normal? How does it smell? Have you had the SES code pulled?

Thank you for the reply. I have performed the schedualled maintenance as directed by my owners manual. I usually change the oil every 5000 miles. All work has been done at my local Chevy dealership so as to avoid any potential problems, so they have the complete maintenance history. I called the dealership and will be taking it in tomorrow. The service writer seemed to think that I had an injector issue so I hope any work will be covered by warranty.

When I change the oil, it is usually black. The service people say that it looks ok. I dont know what it smells like since I dont change it myself. I may start though. Other than this, it has been a very good truck. I'm getting ready to tow my fiver to Las Vegas next month so everything needs to be good.