Why are O2 sensors important in emissions control?

Oxygen (O2) sensors play a critical role in emissions control by monitoring the air-fuel mixture in the engine. By providing real-time data on the amount of oxygen in the exhaust gases, these sensors help the engine control unit (ECU) adjust the fuel injection and air intake. This adjustment ensures the engine operates with the optimal air-fuel ratio, which is crucial for producing complete combustion. When the mixture is optimized, it not only enhances engine performance and fuel efficiency but also minimizes harmful emissions like carbon monoxide, nitrogen oxides, and hydrocarbons. Therefore, O2 sensors are essential for maintaining the balance required to meet emissions standards and reducing the environmental impact of a vehicle.