How does an O2 sensor work?

The oxygen (or O2) sensor is one of the most critical sensors in your car. The O2 sensor's job is to scan the amount of oxygen in the exhaust stream as it exits the engine. This task allows the sensor to measure the fuel mixture. This vital information allows the engine to make the changes needed, so your vehicle runs properly. The beauty in the oxygen sensor lies in the ability to reduce harmful emissions while simultaneously increasing efficiency.

The O2 sensor is continually communicating with the engine to determine if the fuel is burning rich (not enough oxygen) or lean (too much oxygen). At precisely 650° Fahrenheit, the sensor begins to operate. If the air/fuel ratio is rich, it will generate a small amount of voltage (800-1000mv). If the air/fuel ratio is running lean, it will generate an even smaller amount (100-200mv). Think of the O2 sensor as a mini generator. Because the oxygen sensor must become hot before it sends signals, many sensors have heating elements inside to generate heat quickly.

Oxygen sensors are pretty durable, but like many parts, they will wear with age. Contaminants build upon the tip of the sensor, so older parts take a longer time to make changes need for the proper air/fuel mixture. To ensure your vehicle is running as clean and efficient as possible, bring your vehicle to Ferber's Tire and Auto for a diagnostic!