I think your heading in the wrong direction. The IDLE air controller only limits the amount of air entering the engine to control idle speed. Bouncing idle is usually the sign of the IAC acting up.
Oxygen sensors are a wear item, contrary to what many may think. Normal life is 40-60k. Even if they are functioning correctly they start to get slow.
I suggest grabbing a bottle of techron and putting it in at your next fuel stop. Fill the tank 1/2 way, then give your car a good "italian tune up"
Is this most noticable when the car is restarted hot (after driving around and parking for example)?