which catalyst would this one be?

Question

I have the code p0420 and when i go to buy it there is a catalytic coming from the headers with about 6 bolts around it and the other is in the middle of the car almost..

Answer 1

When you set a P0420 what set this code is the downstream 02 sensor or the catalytic monitor sensor . If you hve a scan tool with live data check the 02 sensor , Sensor 2 if the H02S is below 650mv you need a catalytic convertor.

​ Here the downstream or Sensor 2 is used to monitor the catalytic convertor

​ Another downstream H02S sensor monitoring the catalytic convertor

​ A good catalytic convertor , the H02S would stay above 650 mv.