CO Calibration

CO Calibration
The carbon monoxide emission at idle speed is set by specifying adaptation values with the tester on vehicles without emission (lambda) control.

Procedure
CO measurement is to be conducted at the exhaust tailpipe.

Observe the following points:
- Ensure exhaust emission test probes do not leak
- Engine at operating temperature
- Engine running at idle speed
- All additional loads OFF (air conditioning, high beam headlight)
- No fault code stored in engine control module fault memory

Catalytic converter coating on vehicles with catalytic converter provisions
Vehicles with catalytic converter provisions are generally equipped with a catalytic converter. Coating is as follows:
- E38 coated
- E46, E39, Z3 and Z4 not coated
This means that exhaust gas measurement for CO emissions at idle speed on the E38 must take place at the screw mounting points for the oxygen sensors.