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O2 Sensor

  1. Warm engine to normal operating temperature and allow to idle. Connect voltmeter between O2 sensor connector and ground. See Figure .
  2. Run engine at 4000 RPM until voltmeter reads .7 volts. Increase and decrease engine RPM suddenly and several times. When engine RPM is increased, voltmeter should read .5-1.0 volt. When engine RPM is decreased, voltmeter should read 0-.4 volt. Replace defective O2 sensor.
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