Today I filled the truck up and on the way home I stopped at a stop sign. When I took off from the stop sign it would not accelerate very well. A lot of black smoke and the boost did not kick in. The pyro went way up. Turned the exhaust brake off then it run fine the rest of the way home. So I'm thinking the butter fly valve did not shut off like it should. Does this sound about right?

 

very possible