I bought a 07 z truck bout a year ago, put a frame under it and a front end.. Bought it wrecked.. It smoked ever since I built it, I sold it like that to a friend n traded for it back last week.. Truck has 52k miles, 4 inch exaust, stock intake, I put a turbo boost noid on it, a maf sensor, and put a stock fprv in it.. Still pours smoke on a stock tune.. Balance rates are normal, at idle #4 Is .3 more than others.. It runs better than stock, and smokes from 10% to 100% throttle.. I tried lowering main injection pulse until it ran like crap n it still smoked, raised boost helped a Lil.. Turbo vanes r working good also.. Truck is boosting 42 lbs n still smoking.. I can't tell that there has ever been a wrench on any bolts on the motor, they still have the factory paint on em... Please help.. I'm tuning with efi also..

Also tried lowering the max fuel vs rpm.. Lowered it from 200 to 50 and it quit smoking going down the road but idk if it is safe.. Inj pulse is lowered 28% now also..