VNL fault code DTC P22A100??

I've been searching, closest thing I can find is "P22A1 NOx Sensor #2: Short Circuit Low"
With no "00" at the end. Is that the same thing?
Do I just replace the NOX sensor, or is it something else?

 

Checked maintenance history, NOX sensor was replaced 100k miles ago.

 

Do you mean the PDM under the hood on the firewall? All fuses inside that were good, we did find the one on the outside of it was blown, is there another?
Possible issue, truck was taken out of service in February and sat with about 1/3 tank of DEF, and no fuel. I bought it in June and just got it on the road. It needed a park regen on the first trip.
Also, would a loose exhaust clamp at elbow near sensor cause faulty reading? Found loose clamp there and tightened it.

 

Took to dealer, diagnosis; both NOX sensors. Just shy of $2k for them to replace, I bought the sensors, took them home and installed them myself, saved over $400. They have to clear codes and reset computer after the change. All done, no check engine light.

 

Not fixed. Truck needed park re-gen after 5 hours, then wanted another at about 10.
What else could cause it? is the DPF the most likely suspect?

 

I think this might be my problem. This is my DPF, it failed the cleaning due to cores being collapsed. So I had to buy a new one. Will be working the truck today and tomorrow, than a normal schedule next week.
Fingers crossed.

 

Not done yet. Doing the computer reset and regen, the exhaust temps were off, they asked if truck started hard, yeah sometimes it would crank several seconds, other times it would fire right off. Well, that's a symptom of injector cups leaking. So now, another $5k.