Pre-Catalytic Converter Lambda Oxygen Sensor

Pre-catalytic converter Lambda oxygen sensor (R50)
Pre-catalytic converter Lambda oxygen sensor

Function
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 module 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 662 �F (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 module.

The R50 and the R53 have 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.

Installation location
The pre-catalytic converter Lambda oxygen sensor is located on the exhaust in front of the pre-catalytic converter.

Failure
In the event a pre-catalytic converter Lambda oxygen sensor failure, a fault code is entered in the engine control module. The fuel injection switches to pre-activation. The car can display poor running characteristics and rough idling. Poor exhaust purification activates the MIL.