2004.5 to 2005.5 duramax LLY turbo code P0046 and P2563
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 , ***
