Oxygen sensor e.g. lambda sensor, diagnosing method for internal combustion engine, involves comparing actual oxygen filling level of converter with releasing values, where release of signal takes place based on comparison result

摘要

The method involves evaluating a signal of a back oxygen sensor (15) arranged downstream of a catalytic converter (19), and determining an actual oxygen filling level of the catalytic converter, where the catalytic converter is formed as a three-way catalytic converter. The actual oxygen filling level is compared with releasing values that contain higher and/or lower threshold of the oxygen filling level. The release of the signal of the back sensor is carried out for evaluation based on the comparison result. An independent claim is also included for a device for diagnosing an oxygen sensor.