a bad o2 would make it run rich (or lean) but isn't really gonna mess your idle up like that...
knock sensor would throw a code so check the ecu for codes.
reset the ecu and see what happens
get a consult done (if possible)

air regulator would set your idle real high like that if it is busted. Its the thing that sets your idle high to warm the motor up. i don't remember if sr20's have one, but i'm imagining they do. just unplug it, if the idle drops to where it is supposed to be, then you know it was the problem. I personally wouldn't bother replacing it, as this is Florida and all that thing does is help warm the motor up faster, not kike you are trying to warm up in a foot of snow...

 

could be the throttle stop needing adjustment.

 

^

 

i noticed my throttle sticking a bit, going to clean it, maybe the throttle isnt closing all the way, the throttle stop has been adjusted still having same issue.

 

update:
replaced throttle body, didnt fix the idle issue, found out tps was bad, replaced and tweaked the timing a bit, runs flawless.