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Home >> Hyundai >> 2000 >> Tiburon Standard >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls - Self-Diagnostics >> Diagnostic Tests >> DTC P0422: Catalyst Efficiency Below Threshold >> Test Procedures
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Test Procedures

  1. Turn ignition on with engine off. Connect scan tool to data link connector and verify DTC P0422 is set. If DTC P0130 or DTC P0136 and/or P0141 is set, repair these DTCs first. If no other DTCs are set, go to next step.
  2. Start engine and allow to idle. Inspect for exhaust leaks upstream and downstream of catalytic converter. Inspect for exhaust leaks around front and rear HO2S. If no leaks are found, go to next step. If leaks are found, repair exhaust leaks and retest. When repairs are completed, clear DTC and verify operation.
  3. Check rear HO2S operation. See DTC P0130 OR P0136: HO2S CIRCUIT MALFUNCTION  . If rear HO2S is okay, go to next step. If rear HO2S is not okay, perform repairs or component replacement as necessary. When repairs are completed, clear DTC and verify operation.
  4. Turn ignition off. Replace catalytic converter and clear DTC P0422. Road test vehicle and check for DTCs. If DTC P0422 resets, ensure ECM 88-pin connector and terminals are clean and tight. If ECM connector is okay, replace ECM. If DTC P0422 does not reset, repairs and inspection are complete. When repairs are completed, clear DTC and verify operation.
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