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Feedback System Check

  1. Turn "ON" cancel switch, located near fuse block, under left side of dash. See Fig 1 . Turn ignition switch "ON", but do not start engine. Oxygen sensor light in dash should light, but not flash.
  2. If oxygen sensor light does not operate, check light circuitry. Refer to Oxygen Sensor Signal Check section. After oxygen sensor light operates, warm engine to normal operating temperature.
    Fig 1: Location of Cancel Switch
    G42229
  3. Run engine at 1500-2000 RPM and check that oxygen sensor light flashes. If it does not flash, check and adjust or replace the following: oxygen sensor, mixture control solenoid, carburetor idle mixture, thermal switch, electrical connections, ECM or micro switches.
  4. After making sure oxygen sensor light flashes, turn cancel switch "OFF". Oxygen sensor light should go out.