If the engine's operation is unstable, you feel a power loss and notice an increase in the fuel consumption, the lambda sensor has probably failed. Modern cars are usually equipped with two oxygen sensors, one located in front of the catalyst, the other right behind it. When it fails, you should have the lambda sensor changed as soon as possible to avoid serious engine failures and damage to the catalyst. If this happens, the costs of repair will significantly exceed the cost of replacing the probe.
What is the lambda sensor?
The lambda sensor, also referred to as the oxygen sensor, is located in the exhaust system of the car. Its role is to check the amount of oxygen in the exhaust gases and provide the relevant data to the fuel injection controller, which, based on this information, chooses the appropriate fuel-air mix.
How to tell a lambda sensor malfunction?
Some cars are equipped with two lambda sensors, one located in front of the catalytic converter, and one behind it. If a lambda sensor fails, the engine controller receives false data on the composition of the exhaust gases and chooses a wrong proportion of the mix. This results in an uneven operation or surging of the engine. The control light on the dashboard signals a malfunction of the electrical system of the engine.
How is the lambda sensor replaced?
Replacing the lambda sensor requires disconnecting the sensor's electrical plug from the exhaust pipe.
In older cars, removing the lambda sensor from a corroded exhaust pipe may be difficult, so a good idea may be to use a rust remover. When fitting a new sensor, you should cover its thread with a thread paste resistant to high temperatures to facilitate its removal in the future. If, as a result of a failure, the engine controller continues to store the error code, it has to be connected to a diagnostic computer to cancel the error and to enable the engine to operate properly.
What to keep in mind?
Remember that driving with a faulty lambda sensor may cause other components to malfunction, including the catalytic converter.