P0420 Honda - Ridgeline

Question

I plugged in code reader for CEL and received P0420 code Bank 1.  It more refers to the cat.  Not specific for which O2 sensor may be causing this reading, but I assume #2 since it's after cat. My question is, is it likely it's the O2 sensor and not the cat?  I know if I take it to dealer they will tell me to replace all 4 O2 sensors and the cat just ripping me off for all the $ they can get.

Answer 1

Hi there

Most of the time it's a converter issue. If it is a O2 sensor, you are correct it would be the rear sensor on bank 1. I would not allow the dealer to replace ANY of the O2 sensors if they decided the converter was the issue The only time the sensors should be replaced would be in the event they can't get them out of the converter. If that's the case, then it's ok and you would still only be looking at replacing 2.