Truck Runnin Lean

devin_clements1 · January 28, 2009

Hello everyone, im new to this site and this is my first thread. I own a 2003 Silverado SC/StepSide with the 5.3L Vortec. I've been having this problem with it for some time now. Its been throwing codes p0171, p0174, and p0300. Ive replaced the pcv valve, fuel filter, o2 sensors, plugs n wires, etc, etc,. The only other thing i can think of is the intake manifold gaskets. Im at a total loss here guys. Any sudgestions or help would be greatlly appreciated. Thanxs.

dorman68 · January 28, 2009

I would check your intake manifold gaskets for vacuum leaks. The manifolds are prone to warpage and the gaskets are prone to leaking. My coworker had the same issue, his intake gaskets were leaking.