i bought a duramax and it has 110 000km on it.for 2 weeks i feel that is getting slower.when i drive and the engine is cold i dont feel that fast shifting until is getting warm.it is shifting in higher rpm and is hard.i will change the fuel filter, it only has 5000 on it .the air filter i change it already.can you guys give an ideea what can be?converter maybe?thank you