2000 Sierra 1500 4.8L Code P0302

[america964]

I've replace spark plug, wires, coils, fuel filter, fuel pump, and fuel regulator. I've ran Lucas fuel treatment on a few fuel fill ups. This code pops up in the morning. Truck will run rough for 5-10 min and will run normal after. Check engine light will eventually go away within a few hours or days. Was thinking it's a bad or clogged fuel injector on bank 2. Anyone experience this? Thx

[rjgti]

vacuum leak or bad valve

[Duelin]

Intake gasket leaking. And sealing when the engine gets hot. Spray intake around #2 with carb cleaner,brake cleaner,propane or something flammable and see if you hear a change in the idle. And spray again when hot so you can notice the difference.

 

A word of caution. Make sure and do not spray around spark plugs or spark plug wires or coils just in case you have a voltage leak that can cause a fire. Always keep this in mind.

[america964]

Thought about a vacuum leak, will try the starter fluid on the intake and see if that will work. Will update tomorrow .