2004 early 6. Accelerating on the interstate and it just went flat. Torque shows no boost. The boots all look good, no air hissing noises, no unusual noises. Took the intake off the turbo and started it. Turbo spins up and sounds fine, no unusual noises. No codes. I'm guessing a sensor quit, but which one and how to tell? Parked it at Wal-Mart and waiting on a ride.

 

Any codes? Chances are your going to have to clean turbo and look at unison ring. Possible egr valve stuck wide open, plugged cat?

 

The only code showing is for the EGR flow, because its got an EGR delete on it. According to readings on Torque, the vanes seem to be free because the VGT reading changes as it idles, and if you press on the accelerator. It starts fine (well, hot anyway, don't know about cold), idles smooth, press on the accelerator and the engine speeds up ok, no miss, no cough, nothing. There's little to no power when you try to speed up though, and the boost reading never changes from about 1.3. Earlier it had been fine, and the boost reading would go up as expected. Would the MAP sensor do this?

 

Yes the MAP and look for splits in the hose , try cleaning the little nipple that screws into the Intake , also the EBP and tube