Hi all,

I’ve had these two codes on my truck for the past year and have had no luck in trying to resolve the issue. Truck runs pretty good and for most of the year I’ve just put it off. What I have done though is replaced the O2 sensor, the afm/bench tested the one before and new one. Adjusted the tps per the FSM and checked for vacuum leaks. The problem has not occurred until after rebuilding the top end with lce +1 valves (complete head), lce cam, new timing chain. Other mods that it has are full lce exhaust/header, EGR delete, oversize throttle body, cold air and an aluminum radiator. I have not tested fuel px nor injectors. I had a slight thought it might be the FPR however the diaphragm seems to hold vacuum and the idle also changes when I apply vacuum to it. Any help is much appreciated!