Help Idle problem

I have an 02 cavy 2.2 and my idle seems choppy. I'll come up to a stop light, or sign and if i wait for 10 secs or longer the idle will start to jump around, from like 500 to 700 back down to like 300 and so on. I put new plugs in it 6 months ago along with air filter and also ran some injector cleaner through it recently and i still get the problem. I was wondering if it could be the wires, cap, rotor, or plugged fuel filter?
thanks for the help.
chas

try cleaning the throttle body and idle air control passages

cool thanks ill try it but last time i checked everything was clean.

possibly the Idler air control valve? Had that happen in my dad's truck. Same Symptoms.

Probably either fuel flow or ignition related. Crappy coils, bad connection to the battery, cheap plugs, bad wires, clogged injectors, fuel filter, somthing along those lines.