Im having a few problems with my truck, but no check engine light or anything is coming on. Well what basically happens is when my truck is cold, you press on the gas and nothing really happens, it starts to accelerate really slow, and will have little spurts of power, and then nothing. Its sorta bogging down and feels like its about to fall on its face. Another problem i have is with the gas gauge, it goes crazy on me, but from what i read its the sender units. Should any of this bring on a check engine light or some sort of service light? Any suggestions would be appreciated! PS its a 1999 2wd sierra with 4.8L auto tranny.