I have a 03 silverado ls z71 with a 5.3. Ive had this performance issue since i bought the truck in feb. I have replaced intake gaskets fuel pump and filter cats maf map tps plugs and wires air filter and i have thoroughly cleaned throttle body. The truck starts fine and is drivable but has no power. Example..if your cruising at lets say 40 mph and you slowly depress the pedal there is no change or very little and to pass a car or climb a hill you literally have to almost floor it until it kicks into passing gear. also you can feel like a surge and tack flucuates slightly. Any help with this matter would be greatly appreciated so i can have my life back!!!!! lol

$100.00 cash to the person that figures this out. Id be soooo relieved and grateful!!!!

 

do you have access to a scantool?

 

Are you getting a check engine light? How many miles on the truck?