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 .