Air Fuel Ratio (A/F) Sensor

The A/F sensor operates over a wide air/fuel range. The A/F sensor is installed upstream of the three way catalytic converter (TWO. It sends signals to the ECM/PCM which varies the duration of fuel injection accordingly.

Fig 1: Identifying Air Fuel Ratio (A/F) Sensor

Courtesy of AMERICAN HONDA MOTOR CO., INC.