2004.5 to 2005.5 duramax LLY turbo code P0046 and P2563

silverado 2500hd
crew cab lb 4wd

A bad sensor can be the cause but often ithe unison ring inside the turbo will stuck by carbon ( thanks EGR systems) you need to remove the turbo OR you can try this

Step 1 : take te code using a scanner ( i use Autel code scanner )

Step 2: remove resonator box on top of the engine

Step 3 : take a extra long 21/64 drill ( or Q) and make a hole in the bottom of the turbo exhaust side ( near the midle turbo clamp , you should pass between the turbo sensor and the oil fitting on top of turbo )

Step 4 : make 1/8 pipe tread in that hole

Step 5 : put foam penetrant and release agent in that hole

Step 6: put 1/8 plug on that hole and let it sit 24 hours before starting engine

nb: at startup it will smoke a lot and it's normal , should stop smoking after 15 minutes

Maybe could take 2 or 3 treatment to release the unison ring , if it doesnt work , you'll need to take the turbo off ....

*** Picture will be include soon , ***

Boosted Wrenches :Well first off the EGR isn't the culprit of soot buildup in in the turbo, the EGR causes soot buildup in the intake. A diesel will always build soot in the exhaust side regardless of an EGR or not. I also do not recommend your procedure at all as from my understanding you're recommending drilling into the turbine housing which can consequently put shavings into your turbine wheel and cause damage if you're not careful. The correct procedure is to remove the turbo and disassemble the turbo to clean the unison ring and vanes for the VGT.