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Sub-Oxygen Sensor Test

  1. Inspection is required when trouble code No. 27 exists. Clear trouble codes. See CLEARING TROUBLE CODES under TESTS W/CODES article in this section. Warm engine to normal operating temperature.
    CAUTION: DO NOT  exceed 62 MPH or trouble code will be cancelled.
  2. Drive vehicle between 50 and 61 MPH for at least 5 minutes in 4th or 5th gear (Man. Trans.) or "D" range (Auto. Trans.).
  3. Fully depress accelerator pedal for at least 10 seconds with engine RPM at least 3000 RPM.
  4. Stop engine and turn ignition off. Repeat previous steps and note if trouble code No. 27 exists again. If trouble code exists again, check sub-oxygen sensor circuit for continuity, shorts or grounds. Replace sub-oxygen sensor if circuit is okay.
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