Guys I have this problem with my truck.At idle it seems to be misfiring.It doesn't do it all the time.When it gets warmed up and I drive the crap out of it it will start.At idle it will just sit there and stumble,give it a little gas to about 2000rpm and it still does it.I have had it at the dealer where I bought it they put it on the tech II it didn't show and misfire code and they said all the sensors were operating correctly.I have changed the plugs and wires and still no change.I descreened the MAF and cleaned it still no change.My friend is a GM mechanic,he recommended cleaning the injectors out I let him do that and still no change.H esaid that 2 were really dirty.Guys I feel this stumble is hurting the performance of my truck and I am just tired of it missing.Any ideas what it might be.

 

I forgot to mention that I have true dual exhaust with an H pipe and was told that it might be the culprit.What do you think?

 

i dont think the exhaust is the culprit. how did he clean them. did he clean them at the dealer where they flush them completely?. if not i would do that.how gummed up is the tb. i have seen that do it as well. also take out the tuning and see what happens also.

 

Does it go away after 2000 rpms?? Could be a vacuum leak somewhere?

 

He took them to the dealeship and back flushed them and sprayed them out with cleaner.I have took the tune out that is the only way the techII will check it,or at least that is what he told me.I thought about a vac leak but seems it would do it all the time with the vac leak.Or do you think it could be the gaskets getting hot and loosing there seal.