rpm weirdness

when my car is idleing for a little bit any time the rpms move around like up and down. it sounds like the car is havin trouble gettin somethin it needs. has anyone ever heard of this? what can i do to fix it?

also when i drive and givin it alot of gas then i let off the gas it feels like the car is pulling back for just a second then it loosens up. it does this a few times. its almost like its down shifting but its an automatic and it does it more than 4 times. i cant figure it out??

well autos downshift...
Check the ECU codes first... if nothing then,
clean and/or replaced the old parts like:
Spark plugs
Fuel filter
Air filter
Cap & rotor

My brothers Prelude had THE SAME problem...it is your throtle body assembly on your PGM-FI...hope this helps