DTC P0420: CATALYST EFFICIENCY BELOW THRESHOLD Kia Sephia I рестайлинг

Catalyst system efficiency below threshold code may be set by

1. Three-way catalytic converter deterioration.
2. Exhaust system leak.

1. Check rear HO2S. See HEATED OXYGEN SENSOR in «SYSTEM/COMPONENT TESTS»(ref-25100) article. Replace as needed.
2. Check exhaust system for leaks. Repair or replace as needed. If no problems were found, replace three-way catalytic converter.