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Home >> Pontiac >> 1990 >> LeMans Base >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - System/Component Tests >> Engine Sensors & Switches >> Exhaust Gas Oxygen (O2) Sensor
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Exhaust Gas Oxygen (O2) Sensor

  1. The O2 sensor is mounted in the exhaust pipe, below exhaust manifold. Measure voltage between pigtail connector and ground. A Scan tester may be used to measure voltage when in closed loop.
  2. Ensure engine is at normal operating temperature. Run engine for 40 seconds (minimum) and measure voltage. Voltage should be 0.1-1.0 volt. If voltage is not within specification, replace sensor.