The advent of the 80's has seen the introduction of another important automobile innovation – the oxygen sensor. This gadget forms part of a vehicle's emissions control system and is also responsible for feeding data to the engine management computer. It does this by checking the exhaust hundreds of times per minute. In a nutshell, the car oxygen sensor helps maintain optimum engine performance and lower a vehicle's smoke emissions.

The oxygen sensor is strategically located in the exhaust pipe. As such, it can easily detect the presence of rich and lean mixtures. Most O2 sensors also contain a mechanism that produces a chemical reaction that generates voltage. Knowing the amount of voltage present is critical to determine whether the mixture is rich or lean. The engine's computer then makes the necessary adjustment to the volume of fuel going to the engine.

Among the types of oxygen sensors currently available are the single wire oxygen sensor and the heated oxygen sensor. The latter has a built-in heating ingredient designed to maintain an engine's ideal operating temperature. Four factors should also be considered to extend the longevity of the oxygen sensor: good electrical connections, outside air supply, proper operating temperature and the use of unleaded gasolines.

Engines rely on the oxygen sensor as the amount of oxygen it can pull depends on various factors like altitude, engine temperature, air temperature, engine load, barometric pressure among others. A malfunctioning car oxygen sensor prevents the engine computer from reading the correct air/fuel ratio. When this happens, a vehicle tends to perform poorly and ends up wasting more fuel.