The P0420 (whose official onboard diagnostic definition is ‘Catalyst System Efficiency Below Threshold’) code is a sign that a vehicle’s catalytic converter is subject to one or more problems. Such ...

P0420 is a well-recognized error code within the automotive industry, notorious for its persistence. Luckily, this article is designed to guide you through ...

As an experienced service advisor, I saw the P0420 “check engine” light code hundreds of times. This fault code indicates that your car’s catalyst system isn’t performing as efficiently as it should.

Your oxygen (O2) sensors are small but mighty — they help your engine run efficiently, cut emissions, and prevent costly damage. With the right OBD-II scanner and a bit of know-how, you can decode ...

Maintenance is an essential part of owning a car. Whether it’s simple tasks like an oil change or bleeding your brakes, plenty of jobs are DIY-friendly and can save you the costs of taking your ...

These have at least three oxygen sensors in the exhaust system and when it all starts to go haywire you are in for a nightmare. If you "recently purchased" the car and it is not running properly, then ...