05REDLLY
06-08-2010, 07:21 PM
I have a friend with a 07 lbz, it is blowing alot of black smoke with a stock tune. He checked and found a boost leak at intercooler boot and fixed it. We can't find anymore boost leaks and the truck still blows excessive black smoke. The egts are normal and doesn't seem to have a boost leak, so what else could it be? What are the signs of a cracked piston? Also we did a flow check of the injectors and they were all within spec. I am at a loss here. Any input would be appreciated. One more thing is he has a finger stick in it but to out the blocker plate incase it needs to go to the dealer, and the truck use to have a PPE+2 on it and he would drive it around on tune 6 for a while. Other mods to the truck are exhaust and intake.