The introduction of Saturn to the market was another success for General Motors. Reason for that achievement was the fact that the first Saturns ever to enter the industry were of solid performance. They have the attributes enough to stand against the expansion of the Japanese imports to the US by that time—sleek styling, great handling, ample power, and comfortable ride. And to be worthy for the money that customers would be spending, the engineers molded the vehicles with the ability to produce lesser toxic waste materials, so that they don't only get quality performance but also an environment friendly travel buddy.

One of the effective ways of reducing harmful elements in the exhaust is the use of Saturn oxygen sensors. This device works by accurately checking the red-hot exhaust hundreds of times per minute in order to help the emissions control system to produce the least exhaust gases as possible. It informs the driver the amount of oxygen present in the exhaust mixture and sends the data to the vehicle computer. Basically, the presence of oxygen in the process of combustion is necessary in order for the fuel to get burned. Thus the use of oxygen sensors is very much valuable for the purpose of monitoring.

An oxygen sensor is positioned in the exhaust pipe. With its location, the instrument can effectively detect and measure the oxygen content before it leaves the cylinder. The chemical reaction that the sensor produces generates voltage, which then determines if the mixture is lean or rich and adjusts the amount of fuel entering the engine for balancing. When lesser air is present than that of perfect ratio, the exhaust system would fail to burn all the fuel. The mixture produced with the kind of ratio is called rich mixture which results to pollution. And if there's more air in the combustion, the mixture is considered as lean mixture. In the same way, the result is more pollutant elements or nitrogen oxide, and may actually lead to poor performance or worse, create engine damage. If the sensor fails to execute its operation properly, the computer then would end up guessing the air and fuel ratio and consequently also fail to adjust fuel amount. The sensing ability of a Saturn oxygen sensor can be affected by altitude, air and engine temperature, barometric pressure, engine load and some other aspects.

A Saturn that's equipped with a gasoline engine has a perfect ratio of fuel and air of 14.7:1. Imperfect fuel and air ration results to black smoke from the exhaust, smell of rotten egg, and/or poor mileage. But there's actually no specific or standard perfect ratio for all vehicles. The perfect ratio depends on the type of engine that the automobile is using and of course, Saturn oxygen sensor itself. Oxygen sensor is also known as O2 sensor, lambda probe, lambda sensor, lambda sond or EGO sensor.