B18c2. Stock.

Symptoms:

* Low idle (300-400 RPM) after warm up. Warm up idle is normal and car idles normally for a short time before completely warming up.
* Never stalls. Seems happy to live life at 300 RPM.
* Not jumping/hunting. Just sits there steady.

Things I've tried:

* Cleaned the ICAV a couple of times. Was not blocked etc.
* Replaced coolant and (I think) bleed and air-purged it.
* Visually checked the vacuum tubing, seems fine.

I don't wanna go messing with the idle control screws as it was fine for a long time, haven't changed anything significant.

***Any ideas before I just replace all the vacuum tubing? Really need tiny friggin' hands to get to that little black box under the intake :P