Help please, RoadTrippin P20EE code

[Turbonetics TQ]

I am on a road trip and logged a P20EE on my stock 2013 RAM3500. In almost 70 gallons of Diesel I have not used any DEF. I am pulling an empty flatbed trailer.
Does anybody know if there is a filter between the DEF tank and the doser nozzle? Or am I looking at possible pump or doser valve issue?
Or has anybody had experience with this? The truck has 44,000 miles on it and it almost never goes anywhere without a trailer. And minimal idle time.
I seem to usually go through a 1/2 tank of DEF to a tank of fuel when I am loaded heavy. But this is my first long trip with this truck.

....kinda missing my old faithful VP truck.

Thank you!!

 

[Turbonetics TQ]

Pulled out the dosing nozzle and it was plugged off with crystallized DEF. I cleaned it out and put it back together. It seems to be working again and no code!

 

[Hired Gun]

How is it going? I just got this code Saturday in Bowling Green, Ohio. When I got back I pulled the code, and it said catalyst bank 1 deficient . I was told I needed a PCM update that might solve the issue. So Friday I take it in to have it done.

 

[Turbonetics TQ]

Just pull out the dosing injector and see if urea has "caked" the hole where it injects in to the exhaust. It's just 2 bolts and its out.
I drove 1100 miles back after and used 8 gallons of DEF. I did not use any on the way out.
Dodge dealer in Tooele UT told me it was the DPF so I needed to drive it on the interstate......SCR catalyst is after the DPF and the code had nothing to do with the DPF.