Any ideas on catalytic converter problem. Earlier I had problem with 2 oxygen sensors and replaced. Later getting service engine soon light and the problem is P0420 and P0430 codes which is catalytic efficiency below threshold Bank 1 and Bank 2 respectively. I want to understand the root cause of these problems or do you think just replacing catalytic converters will be fine. I heard if there are other engine problems the light will come again with new CATs as well.
Any ideas?