Misfire or Rough Running

Check:

1. Fuel Supply
a. Fuel Injector (16)
b. Pressure Regulator
c. Contaminated Fuel
2. Electronic Air Control Valve (EACV) (14)
3. Exhaust Gas Recirculation (EGR) System (12)
4. Electronic Control (ECU) Unit (BU)

NOTE:
After each symptom, the system that could be the source of the symptom are listed and should be checked in the order they are listed, beginning with #1.

(BU) code used when the CHECK ENGINE warning light is on, and the self-diagnosis indicator LED is ON with no "blinks", the back-up system is in operation.

Self-diagnosis indicator, (LED) blinks (?), will follow associated systems.