Posts Tagged: test a catalytic converter

A DIYers guide to the dreaded P0420 catalytic converter code

What to do when you get a P0420 catalytic converter code If you’ve got a check engine light with either a P0420 P0420 catalytic converter code or a P0430 trouble code, don’t automatically replace the oxygen sensor. Why? Because a herP0420 catalytic converter code is almost NEVER caused by a bad oxygen sensor. Here’s a step by step guide to dealing with a P0420 or P0430 code Why it’s never the oxygen sensor Here’s how the computer tests the efficiency of your catalytic converter. Once it’s up to operating temperature, … Read More