Okay, so I’ve traced my idling problems back to a vacuum leak, based on the following:
My idle drops when I press the brake pedal, and goes back up when I release it.
What I was wondering, is how many vacuum lines does a DOHC KA have, and where are they located? Is it just the ones that run underneath the intake pipe, or is there more?
I looked in the FSM (duh! haha, can’t believe I didn’t think to do that right away) and I cleaned up my vacuum lines a bit. Unfortunately the idle problems did not go away. On the plus side, my car now actually has a top end. It used to kinda stop building power past 3k rpm, and now it’s completely different. It all of a sudden gets louder when I go past 3500 and pulls quite hard. It’s almost like I have VTEC 
I’d put my money on your problem being the IACV (which is located on the Intake Manifold) between the 3rd and 4th Runner.
They are known to cause alot of idle issues (not just on Nissan) but more so on Honda Engines… I know my Integra had a faulty IACV and once replaced it was a night and day difference…
Do you think the dealer would still carry that? And would it be an uber-expensive item, or something reasonable? (like under 100 bucks)
you can try spraying carb cleaner in the IACV to see if it helps it. but it dosent sound like a IACV problem.
how does your car cold start? normally?