Setting codes, No power, Surging

[maddenjr]

I have a 05 6.0 here and the truck is acting up. No check engine light on but does set some codes. PO299 TC/SC Underboost , PO478 Exhuast Pressure control valve high , P1408 EGR Flow Out of range , P2263 TC/SC Boost system Performance... I took out the EGR valve and it was clean and replaced not that long ago. The oil temp and coolant temps are staying very close to each other. Truck is making over 40psi but wont get out of its own way and the exhuast sounds weird. I think it might have a problem with the turbo or wastegate. Any ideas guys?

[dannyboy950]

Un less you accidently posted in the wrong forum. A 6.0 has no wastegate, it has a variable geometry turbo. Basically it can adjust the amount of exhaust gas going thru the turbo at any given time.

You probably have a dirty sticking turbo that needs cleaning and probably some intake or CAC restriction. You are showing signs of both overboost and underboost conditions.

When was the last time you changed the air filter. Check your CAC boots at the cooler and at the turbo. Check for exhaust leaks at the flex pipes, uppipes and turbo clamps.