An Oxygen sensor is sometimes called a Lambda sensor or probe, it is used to lessen emissions from a vehicle by guaranteeing that the engine burns its fuel well and clean. Robert Bosch GmbH which is one of the world's biggest automobile components supplier was founded by Robert Bosch in 1886, and was responsible for the introduction of the first Lambda sensor/probe or oxygen sensor in the year 1976.

Oxygen sensors that are used for automobiles are generally referred to as O2 Sensors and after the first one was pioneered by Robert Bosch, Volvo and Saab, which is a manufacturer of automobiles, but which General Motors is now the proprietor of, decided to be the first set of companies to use an O2 sensor in their vehicles; this was within the same year the oxygen sensor was introduced. The O2 sensors were not introduced into the United States until about 1980, and in 1993, oxygen sensors became a requirement on all types of cars within many European countries.

Engine Control Unit which is abbreviated ECU or Power-train Control Module which is abbreviated PCM is a computer programme for motor vehicles that supervises the timing of the ignition, the amount of fuel and other factors that is essential for an internal combustion engine to operate. It collects data on oxygen concentration and then makes adjustments to the quantity of fuel that is injected into the engine to balance the level of air and fuel. The purpose of the ECU is to sustain a certain Air-Fuel Ratio by decrypting the data it collects from the oxygen sensors.

The component of the O2 sensor is a cylinder that is ceramic with porous electrodes from platinum laminating both the inside and out then the entire thing is further plated in gauze made of metal. The oxygen sensor or probe functions by getting a measurement of the ratio between the oxygen in the gas, in the exhaust and the external air, it then makes an adjustment that is dependent on the result that it acquired from the measurement.

The sensors will only function efficiently when they are heated to an approximation of 316 degrees Celsius or 600 degrees Fahrenheit; therefore the companies have started to make the more recent probes with heating components enclosed in the ceramic that makes the cylinder, in order for the sensor to heat up more quickly to the required temperature. The probes that were made without the heating component would reach the required temperature after a while, but took a little time as it had to depend on the heat from the exhaust, in addition there are elements in the engine that is made to absorb heat, so it took a while for the exhaust to get to the correct temperature to allow the older model oxygen sensors to work.