Circuit/System Testing
- Diagnose any other DTCs that are set. Refer to Diagnostic Trouble Code (DTC) List - Vehicle .
- Inspect the air induction system for the following conditions:
- Modified, damaged, leaking, or restricted components
- Dirty, missing, or deteriorating air filter element
- Inspect the crankcase ventilation system for proper operation.
- Inspect the vacuum hoses for splits, kinks, and proper connections.
- Inspect for vacuum leaks at the intake manifold, the throttle body, and the injector O-rings.
- Test for fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
- Test for excessive fuel in the crankcase.
- Test the fuel injectors. Refer to Fuel Injector Diagnosis .
- Test the ignition system for proper operation. Refer to Electronic Ignition (EI) System Diagnosis .
- Test for a restricted, damaged, leaking, or modified exhaust system. Refer to Symptoms - Engine Exhaust .
- Test the engine for any mechanical conditions which could cause an air/fuel imbalance. Refer to Symptoms - Engine Mechanical .