Its right buy the throttle body, should be a brown harness, the iac itself only has two screws that hold it to the intake manifold.You could also try cleaning your egr valve, that sometimes helps.
I had the same problem, is was my idle air control valve, not the actual valve but the harness that connects to it became frayed. once the car was warmed up it would stall out. All i did was splice the wires back together and it ran fine. I hace the perrin fmic with hks ssqv and Apex 3'in...