Posted on 6/27/2025
When most drivers think about fuel economy or emissions, they tend to focus on visible components, such as the engine, air filters, or exhaust. However, one of the most influential parts in regulating how your car burns fuel and controls emissions is something small and often overlooked: the oxygen sensor. The oxygen sensor, or O2 sensor, monitors the level of oxygen in your vehicle's exhaust gases. This information is critical to how the engine control unit (ECU) determines the air-to-fuel ratio. If the sensor isn't working properly, it can throw everything out of balance, affecting how efficiently your car runs and how cleanly it burns fuel. How the Oxygen Sensor Works Your car’s engine needs the right mix of air and fuel to operate efficiently. Too much fuel (a rich mixture) or too little fuel (a lean mixture) can reduce power, harm fuel economy, and increase emissions. The oxygen sensor sits in the exhaust system and measures how much unburned oxyg ... read more