new exhaust applied week ago on my town and country, p0420 still?

Question

the check engine light is on
so i went to autozone to check that
and they gave me a report that the p0420
catalyst efficiency below normal bank 1
but 2 weeks ago ane catalytic converter was applied to my car
and after 2 days the engine light is on.

Answer 1

P0420 is catalytic below threshold Bank 1, This is where a 02 sensor has to be checked When it comes to the Chryslers if you install new 02 sensor upstream which is before the catalytic convertor with old rear 02 sensor you will set a P0420 code, Why the 02 sensor downstream sensor is in the middle of the catalytic which is suppose to monitor the whole catalytic convertor, ? This is a typical code to set, History of the vehicle, if there is new front 02 sensor you need to replace the downstream as well.