Finally took the truck in after three months of P203 code popping every 20-70 miles.
Didn't know the cost, but was ready to pay.
They did a diagnostic, need to replace the DPF filter, O2 Sensor, Catalytic Converter, DEF Sensor and DEF tank.
About four years ago I agreed to allow the ECU reflash...
Electrical gremlins are tough, especially in this canbus era where every signal goes to so many places.
If you can gain access to a DC amp meter, (ameter), you might isolate the source yourself.
With engine off.
Make sure meter is set to DC
Put clamp around each of the cables, one at a time...
I have a 2014 Laramie Longhorn Ecodiesel. I'm around 110k. I appreciate your post, as I did not receive the recall notice either.
I opted out of the class-action, only to have the swirl-valve fail. It was either eat a $3,500 repair bill, plus rental, or agree to the ECU flash, and get the repair...
I got the code 10 minutes after filling up. Cleared it and 1 1/2 days later it came back on.
That was around 105,000.
Made an appointment at the dealer, but it was for two weeks out, so I cleared it again.
It hasn't come back, and there hasn't been any noticeable issues. I'm now around 107,000...