widebody2

ok this is my friends car and nobody can figure out what the problem is. after taking off the rigid tube that goes to the throttle body, and replacing it...his car has no power. it sounds like abolute crap. He still can make like 8 lbs of boost but the car is pretty darn slow. we already changed the plugs, map sensor, and didn't see any loose vac tubes. what could this be? thanks