Update: I bought a used after treatment system from a shop in High River that had done a delete on a customer vehicle. It came from a 2014 with 10,000 km. Very clean and new. Ours is a 2013.
After removing the the old one, we tested and couldn't get any compressed air through it. It's completely plugged. No wonder the truck wouldn't even start. When I got the newer one to the shop, we noted that there are two nozzles near the rear of the old canister that aren't on the newer one. There are two flexible hoses extending from an sensor mounted on the chassis that ties into the main harness associated with the after treatment canister. We installed the pipe anyway, and plugged the two hoses. The truck started and ran with no codes. Took a short test drive, and still no codes. So now the question: What is the purpose of those two hoses and the sensor? I believe they are measuring back pressure. How long until this manifests itself, and bites me in the butt?
The test drive was held short because of a fan belt squeaking so loudly that I thought I had a seized idler, or alternator. Sounded like a bad exhaust leak also, but maybe it just used to be much quieter because the back pressure was so high due to the plugged DPF.
Now getting a code that the trailer brake module has a fault! Supposed to leave for a trip to the US Monday with a trailer. Not so handy.