I posted the problem last month and have some added information. The truck is a 2002 Duramax with 82K miles, 4" Banks exhaust turbo back, K&N filter, factory tune.

When starting a puff of black smoke is ejected. Idle is smooth without smoke. When cruising the exhaust appears to be clean. Under acceleration black smoke intermitantly is ejected. When under a load (7K lbs) the amount of smoke increases in the same pattern. It is almost like it is spitting out smoke in spurts. When under a load I swear I can feel a "miss" the follows the spurts of black smoke.

The Stealers $95 test indicated no problems. I cleaned the MAS and connector with a MAS cleaner. I replaced fuel filter and cleaned the air cleaner.

Thanks for you help

Jim

 

Without a driveablity concern or rough run it is hard to say if there is anything wrong. Diesels will smoke under load or accel. Depending on what the dealer looked at the balance rates may have been in spec and your fuel rail pressure could have held at 160Mpa. If you develope a idle flucuation it could be your fuel pressure regulator.

 

hmmm something doesnt seem right...the banks kit will smoke mildly on a good day and seein it smoking intermittently doesnt seem right either...it might be an injector which is common to go on the LB7...I believe GM is honoring 100k+ on the injectors so you may wanna take out the chip and see if thats the problem...I know a few people that had them changed...