Conditioning For Sensor Testing

HINT: 

• If the voltage output of either the air fuel ratio or heated oxygen sensor does not fluctuate, or there is a noise in the waveform of either sensor, the sensor may be malfunctioning.
• If the voltage outputs of both the sensors remain lean or rich, the air-fuel ratio may be extremely lean or rich. In such cases, perform the Control the Injection Volume for A/F Sensor Active Test using the Techstream.
• If the Three-way Catalytic Converter (TWC) has deteriorated, the heated oxygen sensor (located behind the Three-way Catalytic Converter (TWC)) voltage output fluctuates up and down frequently, even under normal driving conditions (active air-fuel ratio control is not performed).

Fig 1: Oxygen Sensor Waveform Pattern For Deteriorated Catalytic Converter (TWC)

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