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Sub-O2S (Calif. Emissions)

  1. A malfunction in the sub-O2S circuit will set DTC 27. For testing procedures, see TESTS W/CODES - 1.6L article. Use following procedure to test sub-O2S.
  2. A voltage is produced in response to amount of Oxygen in exhaust gases. A lean mixture (high oxygen content) will produce a low voltage of approximately 0.1 volt. A rich mixture (low oxygen content) will produce a high voltage of approximately 0.9 volt.
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