Repair Procedures

IMPORTANT: A new converter with less than 100 miles on it may set P0420 due to out-gassing of the internal matting. Operating the vehicle at highway speeds for approximately 1 hour may correct the condition.

Exhaust Manifold Replacement (4.2L Engine)
Catalytic Converter Replacement (4.2L Engine) or Catalytic Converter Replacement (5.3L and 6.0L Engines)
Heated Oxygen Sensor Replacement - Position 2
Exhaust Leakage
Restricted Exhaust