Check your vacuum hose coming from the intake plenum to the passenger valve cover towards the rear. Mine was doing the same thing. Cleaned all sensors, changed plugs, no check engine light, O2 sensors working correctly. Ended up being that valve cover vent was completely clogged (pcv?). Plastic valve inside was brittle and broke. Had to pull cover off to drill it out and not contaminate head. Idles beautifully now at 780-800 rpms.

 

I pulled the pcv hose and it looked decent, I might as well take the hose all the way off and clean it..

 

Also check where the hose connects to.

 

I pulled the hose and put a flashlight to the opposite end and was able to clearly see inside, which was fairly clean, not dirty enough to clean imo. Also, which plastic valve are you referring to? Both ends that the pcv hose connects to are metal, and which would be the best way to clean the insides of both?

 

On the passenger valve cover bro. Towards the rear, metal tube sticking out.

 

Oh whoops, yeah I checked the passenger side and it looks like the same thing happened to me, that plastic plug broke off inside so I guess I have to drill it out now?

 

You'll need to remove the rocker cover in order to drill out the plastic piece. Otherwise you will be putting plastic inside the engine to ruin something internally...

 

Well I was able to fish out the broke oil separator after spraying some carb cleaner on it, it still idled high after that, so while it was crunk I unplugged the iacv, cut the truck off, plugged it back in and crunk it, at first it idled around ~200 because of me turning the idle screw prior, but I hopped out and turned it until it sounded right and the tach said ~750. This was after the engine had been warmed up. So far so good

 

Well now it's back to 2k.. Any suggestions?

 

The only way to get it to idle correctly so far is to start it, unplug IACV, shut engine off, plug IACV back in, start engine. Repeat.
And then once it idles correctly, the next time engine is started even immediately after, it resumes to 1500-2000.
Does anybody know what this means?