Causes and Fixes Hyundai P0420 Code: Catalyst System Efficiency Below Threshold (Bank 1) Possible Causes of a Hyundai P0420 Code: Heater Oxygen Sensor Bad catalytic converter Engine problem
Replacing my Catalyst converter on Citroen C1, Peugeot 107, and Toyota Aygo catalyst converter purchased cheap off eBay, don’t pay the daft dealer chargers f…