How to fix code P0420

Question

P0420, 06 Dodge 6.1 Hemi What is the best approach to fix this code. Engine is running smooth, plenty of all range power, this code just keeps returning about every 150 Miles.

What should I do first?

Answer 1

Hi there

 Typically the problem with this code is in fact the bank 1 catalytic converter. Sometimes the rear O2 sensor can be reading wrong and cause the code as well, but generally the converter isn't cleaning the exhaust enough and needs to be replaced.