## Fuel and Emissions Systems

#### Symptom Troubleshooting Index (cont'd)

11-472

Symptom | Diagnostic procedure | Also check for
Misfire or rough running (MIL works OK, no DTCs set) |

1. Check the spark plugs (see page 4-25)
2. Test the fuel pressure (see page 11-431).
3. Test the injectors (see page 11-552).
4. Troubleshoot the fuel pump circuit (see page 11-398).

- Low compression
- Valve Clearance
- Contaminated fuel

Fails emission test (MIL works OK, no DTCs set) |

1. Inspect the three way catalytic converter (TWC) (see page 11-575).*1
2. Check the spark plugs (see page 4-25).
3. Test the fuel pressure (see page 11-431).
4. Test the injectors (see page 11-552).
5. Check the EVAP emission control system (see page 11-580).

- Contaminated fuel
- Low compression
- Slipped/broken timing belt

Low power (MIL works OK, no DTCs set) |

1. Test the fuel pressure (see page 11-431).
2. Check the air cleaner element (see page 11-447).
3. Inspect/adjust the throttle cable (see page 11-449).
4. Inspect and then test the throttle body (see page 11-574).
5. Inspect the three way catalytic converter (TWC) (see page 11-575).*1
6. Test the injectors (see page 11-552).

- Contaminated fuel

Engine stalls (MIL works OK, no DTCs) |

1. Test the fuel pressure (see page 11-431).
2. Check the idle speed (see page 11-560).
3. Troubleshoot the brake pedal position switch signal circuit (see page 11-423).
4. Check the spark plugs (see page 4-25).

- Intake air leaks
- Faulty harness and sensor connections

*1: with TWC model