An oxygen sensor (O2 sensor) is a device that measures the proportion of oxygen (O2) in the exhaust gas of an internal combustion engine. This information is used to adjust the air-fuel ratio of the engine, which is critical for efficient combustion and emissions control.
O2 sensors are typically located in the exhaust manifold or exhaust pipe of an engine. They are exposed to high temperatures and harsh exhaust gases, which can damage the sensor over time. As a result, it is important to test O2 sensors regularly to ensure that they are functioning properly.