Automotive Mechanic Training - Car Repair and Maintenance - How Oxygen Sensor Works in Cars - O2 Sensor Full Explained

How Oxygen Sensor Works in Cars - O2 Sensor Full Explained One of the most important sensors in modern cars is the oxygen sensor. Also known as the O2 sensor because O2 is the chemical formula for oxygen, the oxygen sensor monitors how much unburned oxygen is present in the exhaust as exhaust exits the engine. By monitoring oxygen levels, the sensor provides a means of measuring fuel mixture. The O2 sensor lets the computer know if the fuel mix is burning rich (not enough oxygen) or lean (too much oxygen). Knowing the ratio of fuel to air allows your vehicle’s engine to make any necessary changes to ensure that your car runs like it should. O2 sensors are used as a closed-loop feedback for the air/fuel ratio of an engine, by telling the ECU whether the engine is running rich, or lean.