Individual Operation
A/F Sensor 1
While O2 sensor changes output voltage by ON/OFF (rich/lean) mode within a narrow range of the stoichiometric ratio, the A/F sensor changes output voltage between 0 - 4 V for a wide range of air fuel ratio.
A/F Sensor 1 Heater
The ECM performs ON/OFF duty control of the A/F sensor 1 heater corresponding to condition to keep the temperature of A/F sensor 1 element within the specified range.