Oxygen sensors are
normally tested while
doing a 'tune-up' or
when the check engine
light comes on

Oxygen Sensors

Chances are your car has an oxygen sensor in its exhaust system.  You may never have encountered an oxygen sensor or know what it is used for, but it is a part that requires periodic replacement. Otherwise you may experience poor vehicle performance.

Oxygen sensors are designed to measure the oxygen content of a car's exhaust gases. This information helps the engine-control computer regulate the mixture of air and fuel burned in the engine to provide an optimal balance of power, economy and clean exhaust.

Oxygen sensors are relatively simple to replace. Replacement intervals range from  60,000 or more miles, and are generally referred to in the owner's manual. Sensors should be tested before replacement to confirm that the sensor is not working properly.

You may not notice a difference in the way a car drives with a defective sensor, and assume that nothing needs done until the car 'acts up'.  This can be a mistake, an engine may use more fuel when the oxygen sensor isn't working.  This hurts economically, and creates dirty exhaust, polluting the air. Testing and replacement if needed at recommended intervals assures trouble free driving.