If the P0420 code is combined with other codes it's always a good idea to fix them in order.
Your Catalytic Converter Should Never Have Failed. If It Did, Then You Have A PROBLEM!
To avoid catalytic converter problems, keep the engine up with regularly scheduled maintenance tune-ups and system maintenance per factory recommendations.
Professional Diagnostic OBD II Scanner
https://amzn.to/2NlobKU (Affiliate Link)
STP Gas Treatment
https://amzn.to/2pfXk4s (Affiliate Link)
STP Fuel Injector Cleaner
https://amzn.to/2pewFos (Affiliate Link)
Cataclean
https://amzn.to/2xgs3Tw (Affiliate Link)
📊 Robinhood Free Stock:
https://join.robinhood.com/ralphc473
📉 Webull Free Stock:
https://act.webull.com/t/ikCEAz9mKlh7/apz/
📈 Acorns:
https://www.acorns.com/invite/58XBDB
Disclaimers: all opinions are my own, sponsors are acknowledged. Links in the description are typically affiliate links that let you help support the channel at no extra cost.
Possible causes:
A damaged or faulty oxygen sensor
Fuel injectors may be faulty
Fuel injector leaks
Spark plugs may be faulty
Improper ignition timing
Engine Control Module
Exhaust pipes damage
Catalytic converter itself
Oil or Antifreeze entering the exhaust system
Cat efficiency drops below 92%
Road Damage or Broken Hangers
Products and Technique I used To Pass Emissions Test
OBD-II Scan Tool
STP Gas Treatment
STP Fuel Injector Cleaner
Cataclean
Ran Engine at High Speed / High RPM's to Burn & Blow Carbon Build up out.
Took Car Right To Emission Test Station
MY CHOICE / NOW, WHAT'S YOURS? Please Subscribe, Like and Share my Videos.