Recenly had my cat switch out and my 02 sensor code p0420 still showing on the obd scanner

Question

Hesitates around 40 -45 mph changed out the 02sensors and cat still getting p0420 code

Answer 1

Hi there,

Here is a list of possible causes for this code.

P0420 GMC - Catalyst System Low Efficiency Bank 1

Read more: https://www.autocodes.com/p0420_gmc.html