What is the function of an automotive oxygen sensor?

@giles.heathcote 

The function of an automotive oxygen sensor, also known as an O2 sensor, is to measure the amount of oxygen present in the exhaust gases coming out of the combustion system in a vehicle. It is located in the exhaust system before the catalytic converter.

The main purpose of the oxygen sensor is to monitor and regulate the air-fuel mixture in the engine by providing feedback to the engine control unit (ECU). It measures the oxygen levels in the exhaust gases and relays this information to the ECU, which then adjusts the fuel injection and ignition timing accordingly.

The O2 sensor helps ensure that the engine is running efficiently and in compliance with emission standards. By continuously monitoring the oxygen content, it allows the ECU to maintain the ideal air-fuel ratio for optimal combustion and reduce harmful pollutant emissions. This helps to improve fuel efficiency, reduce emissions, and prolong the life of the engine and the catalytic converter.