2005 5.9L 104,000 miles with G56 trans. Everything is stock save for MBRP cat back exhaust.

Symptom: Driving under throttle and acclerating the tach jumps (surges) no power increase whatsoever, noticable turbo engagement. This typically happens at around 1700 RPM's or just under 2000 RPM's.

Cause and effect or where to start looking first?

NMany thanks...JW.

 

Possible causes without knowing codes. APPS(throttle sensor), Fuel pressure sensor, or fuel pressure regulator.

 

I attempted to pull codes by cycling ignition on - off, on -off and the odomoter showed - - - -, the said "done" and the mileage returned.

Ideas?