An oxygen or lambda sensor is used to determine the engine exhaust mixture which can then be controlled by the computer. These sensors are equipped with a heater that can fail causing the check engine light to illuminate. To be sure the sensor is a problem visit how to test an oxygen sensor, a multi-sensor system will be able to monitor the exhaust gasses before and after the catalytic converter.
Most sensors are designed with a heater element to aid the sensors functionality when operating cold. Failure of this element is common and will warrant sensor replacement and trigger a check engine or service engine soon light in most cases. Once the failed oxygen sensor has been located, simply replace the sensor. When an O2 sensor fails it can cause the engine to run lean or rich depending on the failure.
Before beginning, park the car on level ground and allow to cool, block
the tires to prevent the vehicle from moving.
Lift the car with a floor jack
in the manufacturers recommend position, use jack stands to secure the car. Oxygen
sensors are located in the exhaust system so be careful of hot components, wear
protective clothing, gloves and eye wear. Before the oxygen sensor should be removed
apply a light penetrating oil such as WD40 to help prevent thread and sensor damage.
Please watch this video of the job being done, then continue down the guide to glean additional helpful information.
Its important that the wiring harness connectors are exactly the same, each sensor
is unique to it's position and is located in the system by its connector configuration.
Some replacement sensors have a universal electrical connector that must be configured
to the wiring of the old sensor.
After the heat shield has been reinstalled, mount the connector to it's holder
and reattach the connector back onto the wiring harness. If the car has diagnostic
trouble codes, they will need to be cleared.
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