Air/Fuel Ratio

CO Test Port Location:

NOTE: There is no provision for an air/fuel ratio adjustment. The air/fuel ratio can only be checked.

Preconditioning
- Drive vehicle for 15 minutes (minimum). Shut engine OFF.
- Disconnect battery negative cable for ten minutes to clear adaptive memory.
- Disconnect oxygen sensor probe connector (green wire).

Testing
- Remove the exhaust test plug in front of the catalytic converter.
- Connect the CO meter to the test opening.
- Restart the engine.
- Check the air/fuel ratio after the engine has reached operating temperature.
- If the engine is working properly,

Reading should be: 0.4 - 0.8% CO

If the air/fuel ratio is not within specifications refer to DIAGNOSIS AND TESTING PROCEDURES.
- Disconnect the CO meter and reinstall the test plug cap.
- Reconnect oxygen sensor connector.