Rough idle when warm

[FordRanger1991]

I was just wondering if you all can come up with some more things that i could possibly check when i work on my truck this coming weekend.
When truck is warmed up to normal operating temp it seems to want to mess with the rpms. It will jump back and forth from 500 too 800 when at idle. I am also not sure if all my power it there or not.
I have ran some injector cleaner through it and changed plugs and wires.
This weekend i was planning on checking the fuel pressure, running some sea foam threw the break booster vacuum line, and cleaning my IAC.
I am thinking the injectors might be gunked up as they have never been cleaned or removed in its 150k miles and also my number 5 cylinder seams to always be wet. however i just dont want to remove the injectors or pay for some new ones if i can eliminate some other possible problems first.
I would do a compression test but not really a point since the engine block was rebuilt maybe 10k ago.
thanks for your time and ideas
I also will get an engine light if the truck idles for long periods of time however when i give it gas the engine light will leave. KOER test gets me a code 41. I think it deals with engine running rich and o2 sensor but i changed the o2 sensor recently

 

[Psychopete]

41 is almost always never the oxygen sensor at fault. It's sensing too much oxygen in the exhaust. Misfire, vacuum leak, o2 ground, etc. Lots of possibilities. Could be IAC, I would start with vacuum leak. Check that your MAP holds vacuum also.

 

[FordRanger1991]

Well i combed that thing over pretty good and i dont see any vacuum leakage possibilities and all the hoses seem good. After the truck had been sitting for probably 3 hours after running i was looking around and unplugged the break booster line and there was a rush of suction really fast and then it stopped. Could that mean the vacuum lines are pretty good because there was pressure even after sitting that long? (maybe that was a stupid thought...?? lol) but so ya i will clean the IAC. What is an easy way to test if the map is working correctly? should i just unplug the vacuum line to the map when the engine is doing the rough idle? The vacuum line looks like it could be brand new and it seems to have a good connection when i bull the hose of and push it on.
I ran some seafoam through her and she seems to be running cleaner but i still get my rough idle when she is warmed up.
thanks for the time

 

[FordRanger1991]

My fuel pressure seems good you agree?
KOEO 40 psi
KOER 32 psi
When i pulsed the throttle to give it some rpms if bounced up to around 42 psi and then back down when i let the throttle go.
I also took all my injectors out to look at them and all of them clicked when i put power too them and all of their filters were good. However one of them clicked louder then all the other ones... not sure if that is significant...
I cleaned my IAC and so that seems good
still the idle isnt the best after she is fully warm.

 

[FordRanger1991]

Another up date

so i keep the fuel pressure tester with me in my truck so that when my engine begins to do the rough idle at a stop light or something i can just pull over and check my fuel pressure when it is idling bad after being warm. however, when i shut off my truck to plug in the fuel pressure tester and then turn back on the truck idles perfect and wont jump rpms anymore.
so i am thinking that when i shut down my truck if resets whatever makes my truck idle weird. so i am not really thinking that the truck idling weird is because of the heat. because when i restart it seconds later it is still hot...
i am sorta lost
any help would be appreciated!!!!