Air/Fuel Mixture: Testing and Inspection

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

Coil Cover Location:

1. Remove the protective covering for the ignition coils.

Coil Removal:

2. Remove the ignition coils and place them on the engine.

CO Test Port Location:

3. Remove the exhaust sample port bolt and install BMW exhaust adapter 13 0 100 or equivalent at the port.
4. Run the engine until normal operating temperature is attained (>160°F).
5. Shut off the engine.

Oxygen Sensor Connector Location:

6. Disconnect the oxygen sensor connector, which is located under the vehicle.

WARNING: The exhaust system will be extremely hot!

7. Restart the engine.

The CO reading should be approx. 0.7 ± 0.5 %

If the CO level is too high check:
^ DME fault codes
^ Fuel injectors
^ Fuel pressure
^ Coolant temperature sensor

If the CO level is too low check:
^ DME fault codes
^ Intake system air leak
^ Plugged or defective fuel injectors