Do the injectors ever fail under boost pressure only? When my boost hits around 5 lbs I puke a black cloud out the back of the car. The crap is so thick it sticks to the back of the car. It runs great as long as boost presssure stays down. There are no leaks in the turbo side(did a smoke test) and the injectors aren't leaking when tested in the shop? If my afm is shot will it do this? I have had an AFM trouble code for years but this problem is new.