2001 Honda Accord IDLE AIR CONTROL

My car once in a while idle rough when stop at light, also when the car is park I accelerate to 3 to 4 k rpm when I let go of accelerator Padel the RPM drops below idle Momentairly. No engine lights come on.
It has shut down twice. so far no warning or any lights .
1. is it Idle air control circuit valve /
2. or map sensor.?
3. can they be cleaned.?

Please let me know
Thanks sburney