Oxygen Sensor Replacement

Tune-ups aren't what they used to be but, in a sense, that's good. These days, one of the few things that needs to be replaced on a regular basis in a late model vehicle is the oxygen sensor. Putting in a fresh oxygen sensor is easy, not unlike changing a spark plug, although it may be a bit harder to get to in some cases.


Many vehicles have only one oxygen sensor, however newer vehicles may have multiple sensors. Their function is to tell the computer how to adjust the fuel delivery and timing to achieve the best possible burn in the combustion chambers, and they do that by reading the amount of oxygen in the exhaust system. If the oxygen sensor is worn, it can cost you a 10-15% decrease in mileage. With today's fuel prices, that could be a steep price to pay over the course of time, especially since even the high-quality replacement units from manufacturers such as Bosch and Denso are quite affordable for most applications. These name-brand sensors are typically laser-welded and watertight for long life and are available at most decent parts stores. Request a sensor that has a factory-style wiring connection instead of a "universal fit" model (which will require cutting and crimping wires in tight quarters) in order to save installation time.

Smog & Performance
Bosch reports that California Air Resources Board data showed that about 70% of the vehicles tested needed a new oxygen sensor. O2 sensors degrade from carbon, soot, harmful gases, anti-freeze and thermal and physical shock. One- and two-wire sensors wear out after 30,000-50,000 miles, and newer heated-type sensors with three or four wires last 60,000-100,000 miles.


Performance-wise, worn O2 sensors are the primary reason for harmful emissions because they don't send accurate fuel-burn information to the vehicle's computer. Tired oxygen sensors can also cause engine surging and hesitating, and they accelerate catalytic-converter damage.


Don't wait until a failed smog test forces you to do something about that ailing sensor: get improved performance and fuel economy soon, the easy way.