Circuit/System Testing

Engine idling, transmission in Park or Neutral, verify the manifold absolute pressure (MAP) sensor parameter is between 20-48 kPa.
- If not within the specified range .
  Refer to DTC P0106 .
- If within the specified range, inspect for the conditions listed below:
- Modified, damaged, leaking, or restricted air induction system components.
- Improperly operating crankcase ventilation system. Refer to Crankcase Ventilation System Inspection/Diagnosis .
- Split, kinked, or improperly connected vacuum hoses.
- Restricted, damaged, leaking, or modified exhaust system from the catalytic converter forward. Refer to Symptoms - Engine Exhaust .
- Improperly operating fuel injectors. Refer to Fuel Injector Diagnosis .
- Fuel contamination. Refer to Alcohol/Contaminants-in-Fuel Diagnosis .
- Excessive fuel in the crankcase due to leaking injectors. Change engine oil as necessary.
- Improperly operating ignition system. Refer to Electronic Ignition System Diagnosis .
- If a condition is found
  Repair as necessary.
- If no condition is found
Test the engine for any mechanical conditions such as sticking valves, lifters, etc., which could alter the flow into the combustion chamber. Refer to Symptoms - Engine Mechanical .