Do you have a check engine light and when was last tune-up??
Refer to this link for additional information:could be caused by one of the following below
Fuel injectors dirty/sticking.
Mass airflow sensor/Airflow meter.
Throttle position sensor.
Crankshaft position sensor
Manifold absolute pressure sensor.
Fuel pressure regulator leaking or defective fuel pump.
Foul/defective spark plugs.
Open spark plug wires.
Ignition coil/Coil packs defective.
Incorrect ignition timing.
Cap and rotor.
Note:If it doesn't apply disregard it and keep testing.
Sunday, November 6th, 2011 AT 5:26 PM