Hello, referring to my last post, I regapped all the plugs to .040 and that seemed to take care of most of it. Had a p0300 and a p171 codes but now after clearing the codes I come up with a p0306. The SES does not flash and turns off but then will come back on with the same code, sometimes when its cold, sometimes when it at operating temp. No rhyme or reason how long it stays on or off. Truck runs great, no loss of power slight idle roughness when SES light is on but smooth's out when light turns off. Have replaced maf, map, plugs and wires, 2 o2 sensors (down stream sensor giving bad readings) also repaired 2 vacuum leaks and had injectors cleaned. Pcv also replaced. Sorry about the long post, trying to provide as much info as possible. Thanks again!

 

Have you checked for vacuum leaks at the intake gaskets on a cold start? It sounds like you're experiencing the exact symptoms of a vacuum leak at the intake gaskets.

 

Thanks for the feed back, other than a smoke test how else can I check for intake leaks?
I am kinda new at this so any suggestions would be appreciated. Thanks again.

 

If you use a garden hose hose down the intake gasket area during a cold start, it will suck water in, causing steam to come from the tail pipe, and the engine to run extra rough and missfire.

 

OK, tried it and nothing happened. no misfire or change in idle. Was a little nervous about trying it but went ahead using a small stream of water. Maybe I should try again. Thanks for the help.