2. Spark Plugs
3. Ignition Coil
4. Intake Manifold Gasket
5. PCV Valve
6. Fuel Injector/Fuel Filter/Fuel Pump
7. Idle Control Valve/ Throttle Control System (may need cleaning)
8 . Fuel pressure regulator
9. EGR valve needs servicing or replacement and/or bad vacuum hoses connected to and leading from EGR
10. Dirty throttle body
11. Coolant temperature sensor or faulty wiring connection in that location.
12. Faulty Crankshaft or Cam Position Sensor: