An automotive oxygen (O2) sensor plays a key role in maintaining efficient engine performance. A defective oxygen sensor causes a number of engine performance problems, including an increase in fuel consumption and exhaust emissions.
The life of a vehicle's oxygen sensor depends on the specific vehicle model. A general guideline for the sensor's replacement is about every 50,000 miles for automobiles manufactured through 1995 and about every 100,000 miles for vehicles made in and after 1996. The manufacturer's recommended mileage for replacement is noted in the owner's manual for the vehicle.
Oxygen senors often fail early due to corrosion or sediment buildup from matter in exhaust gases. Oxygen sensors may fail more often in engines that burn oil or have similar problems. Engine coolant leaking into the combustion chambers also causes premature failure of an oxygen sensor.
Special sockets are made to remove an oxygen sensor. The sockets have a cutout area to accommodate the wiring attached to the sensor. Oxygen sensors are often sold with an anti-seize compound to apply to the threads before installation. Use of anti-seize compound is important to allow easy removal of the oxygen sensor for future maintenance.
