Preliminary Inspection
- Ensure air intake duct is not collapsed or restricted and air filter is not plugged.
- Check for damaged or partially plugged throttle body inlet screen.
- Check for proper operation of IAC system.
- Check fuel pressure regulator operation, ensuring diaphragm is not ruptured.
- Check for proper operation and mounting of throttle position sensor.NOTE: To complete a trip cycle for fuel trim diagnostic, fuel trim diagnostic test must be enabled and run according to conditions required to set Code P0172. A trip is not considered complete until fuel trim diagnostic has been run by PCM.