You should do a full tuneup first. It'll probably fix your problem.
Plugs, wires, O2 sensor, PCV, fuel filter, air filter. In addition, you should pick up a throttle body gasket (dealer only, about $12 normally) and remove the TB for a thorough cleaning. After the TB is removed, remove the MAF sensor (large black square, 3 screws) and the IAC (idle air controller, it'* the cylindrical black thing). Leave the TPS on the bottom of the throttle shaft.
Clean the MAF sensor filaments GENTLY with a qtip and alcohol (not beer).
Clean the IAC and TB VERY well with intake safe/sensor safe cleaner. Then put it all back with your tuneup. Odds are, it'll run like a champ again.