Reply To: 2021 GMC 1500 Sierra Diesel: Code P2C7a

Thanks for the reply. I have the 1500 DuraMax Diesel. Tech is recommending replace the cat converter. He did not drive the vehicle nor do I have a print-out of the freeze frame data (data the resulted in the code). My thought is it could simply be O2 or NOx. I am hesitant to purchase a cat w/o the other options being explored. I have not experienced the limited speed/milage warning and since the code was cleared a week ago, the Check Engine Light has not come back on.
Are you aware of any online sites (independent of the OEM) where OEM certified techs give non-legal advice about what the steps/processes should be to help with the diag that the tech is giving?
Thanks again for the reply…much appreciated.