my 2000 mazda mpv is reading code p0421 olny what needs to be fixed

Question

How do I fix the promble  when the code reader has one code p0421 what is going to be the right thing to fix

Answer 1

Hi there

This code is for the bank 1 catalytic converter. Most of the time the converter will need to be replaced to resolve the issue. This is the very first converter on bank 1. Sometimes an exhaust leak can cause the code as well as the rear O2 sensor.