Post-catalytic converter Lambda oxygen sensor
Both the R50 and the R53 have two Lambda oxygen sensors, one before and one after the catalytic converter. The signal from the Lambda sensors provides the engine control unit with information on the oxygen content of the exhaust gas. This signal enables regulated fuel injection with an exact stoichiometric fuel-air ratio. This allows the catalytic converter to ensure maximum reduction of pollutant emissions.
The Lambda oxygen sensor starts to operate at 350°C. The sensor has an internal heating element that enables it to heat up quickly. This heating element is controlled by a PWM signal received from the engine control unit.
The R50 and the R53 haven a sensor that reaches operating readiness more quickly by using a lower heater resistor in order to be able to comply with the emissions regulations.
The post-catalytic converter Lambda oxygen sensor is located on the exhaust after the catalytic converter.
In the event of a failure, the poor level of exhaust purification activates the MIL.