Circuit/System Testing
IMPORTANT:
If any DTCs other than DTC P1174 is also set, refer to Diagnostic Trouble Code (DTC) List - Vehicle
.
- Inspect the air intake system for the following:
- Modified, damaged, or restricted components
- Dirty or deteriorating air filter element
- Test fuel injector balance for a rich or lean condition. Refer to Fuel Injector Diagnosis .
- Inspect the base engine for the following:
- The crankcase ventilation system for correct operation.
- A vacuum leak and other un-metered air downstream of the mass air flow (MAF) sensor
- The intake manifold for a leak
- Inspect the exhaust system for the following:
- An exhaust leak
- Damaged, restricted, modified or enhanced exhaust system.
- Inspect the engine mechanical for items that could alter the air flow into the combustion chamber.