Just had to replace the fuel pump after the engine would stall while I was driving, as well as a new maf sensor. Right now the car acceleration is super inconsistent. Sometimes its EXTREMELY slow to accelerate other times its ok and every now and then it sounds smoother and It picks up speed quickly. Any thoughs of what it could be, I have a feeling the cats could be bad as while the fuel pump was going bad I would get some super loud backfires and now I hear rattling near the end of the truck when I drive sometimes.