ORIGINAL BOSCH OXYGEN SENSOR* TO 1,2,3,4-WIRE SENSOR ONLY * Check wires prior to purchase or contact us * An automotive oxygen sensor, also known as an O2 sensor, lambda probe, lambda sensor, lambda sond or EGO (exhaust gas oxygen) sensor, is a small sensor inserted into the exhaust system of a petrol engine to measure the concentration of oxygen remaining in the exhaust gas to allow an electronic control unit (ECU) to control the efficiency of the combustion process in the engine. In most modern automobiles, these sensors are attached to the engine's exhaust manifold to determine whether the mixture of air and gasoline going into the engine is rich (too much fuel) or lean (too little fuel). This information is sent to the engine management ECU computer, which adjusts the mixture to give the engine the best possible fuel economy and lowest possible exhaust emissions. * * * Installation is easy and universal for each model. You need to cut the original harness in between factory O2 sensor & its plug & contact this sensor to the wires coming from the ECU-side plug. Terminals provided or solder contact in place. * * * Failure of these sensors, either through normal aging, the use of leaded fuels, or due to fuel contamination with eg. silicones or silicates, can lead to damage of an automobile's catalytic converter and expensive repairs. O2 sensors are used to reduce vehicle emissions, by ensuring that engines burn their fuel efficiently and cleanly. Robert Bosch GmbH introduced the first automotive lambda probe in 1976. BOSCH sensors outperform any other brand in regarding to reliability and durability.