Idle is messed up

I'm definately not an expert in this but I've heard people having trouble like this ....check the BOV.
Greddy type S has an adjustment thing on the top of it, maybe it's leaking and the engine is sucking air that way ...

just a thought....

check all your vacuum hoses.

sounds like one popped off somewhere.

i had a similar problem last week and i dug around in my engine bay for a good 10 minutes before i spotted the sucker that popped off by the egr valve.

also, you might as well check the rest of them. some off them will slide off if you just nudge them slightly. you should replace all of these loose hoses because they'll probably pop off someday and give you another headache.