So after getting my car out of the shop for having a new fuel pump put in (I don't do wiring lol) I'm driving back having a blast boosting and cruising, then, I push in the clutch and the car goes to 3500rpm and was constantly idling there for 5 minutes until I could pull over. I pop the hood and can't figure it out. Throttle cable was good why is she doing this to me?! I get back home and pop it again and oh look my vacuum hose from my head to manifold is off. I put it back on and bam 900rpm idle.

Always check the obvious guys, no one is too smart to have something dumb happen to them.

 

A very large vacuum leak will also cause the idle to go up and down on it's own (hunting), the exact same way a sticking IAC valve would affect the idle.

-hunting idle after major work, vac leak guaranteed.

-hunting idle that surfaces on its own, sticking IAC rotary shaft, guaranteed.

 

When this happened to me a few months ago, it turned out to be the tps sensor that went bad. wasn't as lucky I guess

 

Aww man that's rough. How much did it run you to replace that? For me it was just a kick in the rear about letting myself not see a vacuum hose (pretty big) just dangling.

 

100 since I Bought a used throttle body with tps sensor. I saw you cant buy it new without throttle body and I wasn't looking to spend 550 new from Honda.

 

Well at least you got lucky in that aspect!