•  A/F sensor: the wide-range air/fuel ratio sensor, which can linearly detect the oxygen concentration (air/fuel ratio of the air-fuel mixture) in the exhaust gas in all ranges, from lean to rich, is used on the A/F sensor.

•  HO2S: detects the oxygen concentration in the exhaust gas.

•  A heater has been adopted, allowing stable detection of the oxygen concentration even when the exhaust gas temperature is low.