Check and test the following below:
Dirty fuel injectors (cleaning the injectors often fixes this).
Bad MAP (manifold absolute pressure) sensor.
Bad TPS (throttle position) sensor.
Bad or dirty MAF (mass airflow) sensor.
Low fuel pressure (leaky fuel pressure regulator or weak fuel pump).
Vacuum leaks (intake manifold, vacuum hoses, throttle body, EGR valve).
Bad gasoline (fuel contaminated with water or too much alcohol).
Sometimes, what feels like a hesitation is actually ignition misfire rather than lean misfire. The causes of ignition misfire may include:
Dirty or worn spark plugs.
Bad plug wires.
Weak ignition coil.
Wet plug wires.
Cap and rotor.
Wednesday, January 20th, 2010 AT 7:14 PM