1999 GMC Sierra 1500 SL 8 Cyl 5.3L - Engine
any common cure for sluggish 5.3 occasionally cant go over 25 mph ?
the truck has 197000rounds on it but engine dont seem tired, it just acts like its starving for fuel or ignition power . You cant floor it, it only gets worse and moreso when the truck is warm . The check eng light is always on and showed lots of codes . So far i've tried replacing maf,tps and the fuel filter and it had a fuel pump not long ago . do you think fuel injectors? Oh and the last owner tried e85 or e20 gas in it .I appreciate your input helping me fix this up. thanks !