Why not just run an ecu diagnostic rather than playing guessing games to see what your problem is? That will give you a definative answer to if your car has a bung AFM. Idling problems can be caused by an excessive amount of things just to name a few dirty/in-op/incorrectly set AAC valve, incorrectly set idle via throttle plate, carbon buildup on throttle plate, AFM problems, air regulator and the list goes on....
Do a seach and that should fix your problem.