Engine Oxygen Feedback Sensor ️

This sensor is essential for keeping the air-fuel mixture correct in Toyota petrol engines. It reads how much oxygen is left in the exhaust gas and sends a signal to the ECU. The ECU then adjusts injector pulse and fuel trim to help the engine run clean, smooth, and economical.

How It Works ⚙️

Mounted in the exhaust stream, the sensing element reacts to oxygen content and generates a changing voltage signal (and on some versions uses an internal heater to reach working temperature faster). When the heater and signal are stable, the ECU can run in “closed loop” for accurate mixture control, better throttle response, and lower emissions.

Why You Need It ✅

A healthy oxygen feedback sensor helps prevent over-fueling, protects the catalytic converter, reduces fuel smell, and keeps the check engine light away. It also supports proper idle quality and consistent power under load.

If It’s Broken

When the sensor is slow, contaminated, or heater-circuit failed, the ECU may default to rich safety mapping. Expect higher fuel use, rough idle, hesitation, black smoke, failed emission test, and possible catalytic converter damage over time.

Compatible Models

• Alphard/Vellfire/Hv
• Estima
• Previa/Tarago