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Home >> Chevrolet >> 2017 >> SS Automatic Trans >> Repair and Diagnosis >> Engine Performance >> System >> Engine Controls And Fuel - 6.2L (LS3) - Diagnostic Information And Procedures >> Diagnostic Information and Procedures >> DTC P0420 or P0430: Catalyst System Low Efficiency >> Circuit/System Testing
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Circuit/System Testing

  1. Verify the conditions listed below do not exist with the appropriate catalytic converter:
    • Dents
    • Severe discoloration caused by excessive temperatures.
    • Road damage.
    • Internal rattles caused by damaged catalyst substrate.
    • Restrictions
      • If a condition is found 

        Replace the catalytic converter.

      • If no condition is found 
  2. Verify the conditions listed below do not exist with the exhaust system:
    • Leaks.
    • Physical damage.
    • Loose or missing hardware.
      • If a condition is found 

        Repair or replace the component as necessary.

      • If no condition is found 
  3. Verify the conditions listed below do not exist with the appropriate B52B Heated Oxygen Sensor 2:
    • The HO2S is not at the correct torque.
    • Damage.
      • If a condition is found 

        Replace the B52B Heated Oxygen Sensor 2 or repair the condition as necessary.

      • If no condition is found 
  4. Replace the catalytic converter.
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