GM Metro/Sprint 1985-1993 Repair Guide

Oxygen Sensor

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OPERATION



The oxygen sensor is located threaded into the exhaust manifold to detect the concentration of oxygen in the exhaust gases. The unit consists of a zirconia element which generates electrical signal, a lead wire which draws out the signal and a cover and housing which protects the element from damage.

Oxygen is introduced into the sensor when the zirconia element is exposed to the exhaust gases. If the concentration of oxygen in the exhaust gases is low, the mixture is rich and the sensor will send a 1 volt signal to the control unit. If the concentration of oxygen is high, the mixture is lean and the sensor will send a 0.1 volt signal to the control unit.

SERVICE



  1. Start the engine and allow it to reach operating temperature.
  2.  
  3. Connect an analog voltmeter between the oxygen sensor electrical connector and ground.
  4.  
  5. The voltmeter should deflect between 0-0.8 volts.
  6.  
  7. If reading is not as specified, refer to "Electronic Engine Controls" in this Section for further diagnosis.
  8.  

REMOVAL & INSTALLATION



The oxygen sensor may be difficult to remove at temperatures above 120°F. Care should be taken not to burn yourself on a hot exhaust manifold.

  1. Start the engine and allow it to reach operating temperature. Stop the engine.
  2.  
  3. Disconnect the oxygen sensor electrical connector.
  4.  
  5. Remove the oxygen sensor from the exhaust manifold.
  6.  
  7. Installation is the reverse of removal. Tighten oxygen sensor to 30 ft. lbs. (41 Nm).
  8.  

 
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