A Brief History Of Oxygen Sensors
Function The oxygen or lambda sensor in a properly functioning exhaust system monitors the A/F ratio, as often as one hundred times per second, and reports this information to the vehicle’s ECU or engine control unit (also referred to as the PCM or ECM). The proper adjustments are then made to ensure that this ratio is ideal or stoichiometric, helping the automobile burn fuel more efficiently. Most oxygen sensors use the core material of zirconia, which produces voltage in relation to the amount of oxygen in the exhaust. Evolution Oxygen sensors were developed by the Robert Bosch Company and first used on Volvo applications in the late 1970’s. Originally, automotive oxygen sensors had only one or two wires and were made from zirconia in a thimble shape. They relied upon the heat in the exhaust system to warm them to their required operating temperature. The problem associated with this concept was that it took a very long time for the sensors to go from nonoperational (thus leav...