Since 1992, European standards require that manufacturers equip cars with catalytic converters to reduce polluting emissions.
Pollutants such as carbon monoxide (CO), nitrogen dioxide (NO2) and hydrocarbon (HC) are the consequence of imperfect combustion, due to an air/fuel mixture that is too rich or too lean.
The role of a catalytic converter is to transform these pollutants into gases that are not noxious to the environment.
The Lambda Sensor optimizes combustion to make it as perfect as possible. Since the catalytic converter only operates within a very precise range of air/fuel mixture for combustion, the Lambda Sensor is the main sensor for pollution control.
A defective Lambda Sensor can cause high emission output and may cause the vehicle to fail the MOT test. Moreover it shortens the lifetime of catalytic converters or can even destroy them prematurely.
A defective Lambda Sensor can generate an increase in fuel consumption by about 15%. Engine performance is also reduced with significant malfunction at low speed and engine stalling when starting.