I have searched a bunch on the forums and I haven't found the issue that I have. My knock sensors were bad so I replaced them along with the intake manifold gasket (Fel-Pro). I cleaned the IAC, and the throttle body. New sparkplugs, 4 new 02 sensors and PCV valve. When I start the car cold the idle bounces from 600 to 400. About a minute or 2 later the idle is steady. Is there a cold start sensor or something else that I need to check? The service engine light came on after all the repairs but no error codes, so I reset it. I let it warm up and it idles and runs fine, its just the first minute or 2 where it does this. no error codes have come up yet. I torqued the intake per the factory sequence to 44 in lbs then another pass to 88 in lbs. I have let the truck go thru a couple heat cycles and have re-torqued the intake to 88 in lbs.
The sparkplugs I used were Bosch 4509 Platinum Ir Iridium Fusion Spark Plug, which per the manual are ok to use, but I don't think that is the issue. So mayby the IAC, TPS, and of course a vacuum leak somewhere?
I could do a smoke test to see if it is a vacuum / air leak.
Here is a video of it when I just start it.
The sparkplugs I used were Bosch 4509 Platinum Ir Iridium Fusion Spark Plug, which per the manual are ok to use, but I don't think that is the issue. So mayby the IAC, TPS, and of course a vacuum leak somewhere?
I could do a smoke test to see if it is a vacuum / air leak.
Here is a video of it when I just start it.