I have a 2005 Duramax when I accelerate it goes but there is a hesitation also it does not stay in a gear long enough to get the rpms up high it shifts into 5th and won’t downshift no matter how far I push the petal down and struggles to stay at 60 mph if I take it out of overdrive it will accelerate to higher speeds I have just replaced the fuel filter and it has a lift pump i also plow snow with the truck and it struggles to spin the tires on ice when pushing snow into a bank it only shows 1 code that returns after I clear them which is 2133 the other codes are just glo plug codes any help I have changed the Throttle position sensor with no change to the code
I am wondering if the turbo could have anything to do with this problem