DriverSide's Car Dictionary has the most comprehensive definitions of automotive terms. This auto glossary can help you decipher what your mechanic is fixing and what the purpose or function of the particular auto part or accessory is for. We have taken the mystery out of automotive service jargon, so that you don't have to.
The bane of owners with "check engine" lights everywhere, the oxygen sensor is a device that can fail with frustrating frequency. This device measures the oxygen level in the exhaust gases, allowing the engine to adjust the air/fuel mixture accordingly. However, each manufacturer uses the oxygen sensor differently--and uses oxygen sensors of varying qualities and design as well, so that a failing oxygen sensor in one car may produce no noticeable affects, while in other cars a failed oxygen sensor (also called an "oh-two sensor" for the chemical descriptor) can radically impact fuel efficiency and overall engine performance--in some cases, the car may not even run. If you're going through oxygen sensors like nobody's business, it's probably a symptom of larger problem, often having to do with an "off" air/fuel mixture damaging the sensor.