Forester F4-2.5L SOHC (2004)
-
The difference in oxygen concentration changes drastically in the vicinity of the stoichiometric air-fuel ratio, and hence the change in the
electromotive force is also large. By using this information, the ECM can determine the air-fuel ratio of the supplied mixture easily. The front
oxygen (A/F) sensor does not generate much electromotive force when the temperature is low. The output characteristics of the sensor stabilize at
a temperature of approximately 700 °C (1,292 °F).