5. Warm up the engine until the engine coolant temperature is 80°C (176°F) or higher.
6. Perform a racing for 5 minutes or more with the engine speed of 2,000 r/min.
7. Connect the digital voltmeter between terminal No. 3 and No. 4.
8. While repeatedly racing the engine, measure the heated oxygen sensor (rear) output voltage.
Standard value:
Engine
Heated oxygen sensor (rear) output voltage
Remarks
When racing the engine
0.6 – 1.0 V
If you make the air-fuel ratio rich by racing the engine repeatedly, a normal heated oxygen sensor will output a voltage of 0.6 – 1.0 V.
note
If the temperature of sensing area does not reach the high temperature [of approximately 400°C (752°F) or more] even though the heated oxygen sensor (rear) is normal, the output voltage would be possibly low in spite of the rich air-fuel ratio.
When the vehicle is driven with high loads, the temperature of the sensing area of the heated oxygen sensor (rear) is sufficiently high. Thus, it is not necessary to apply the voltage to the heater.
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