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Home >> Mazda >> 1994 >> Protege Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Engine Sensors & Switches >> Oxygen (O2S) Sensor
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Oxygen (O2S) Sensor

  1. Warm engine to operating temperature. Operate engine at idle. Disconnect O2S sensor electrical connector. Connect voltmeter between connector and ground. On MX-3 DOHC, increase engine speed to 4500 RPM until voltmeter indicates about .7 volt. On MX-3 SOHC, Protege, and 323, increase engine speed to 3000 RPM until voltmeter indicates about .55 volt.
  2. Observe voltmeter while rapidly accelerating and decelerating engine speed. Voltage should be 0.5-1.0 volt during acceleration and 0.0-0.4 volt during deceleration. Replace O2S sensor as necessary.
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