Sunday on the way to Church in Birmingham, AL, we got the dreaded 225 miles to no restart DEF Quality issue.
Made the 125+ mile trip home, cleaned the Pig nozzle, and still had the error.
Drove it about 20 miles and still no joy. The message had changed from Quality Issue to Dosing Error...

GAP IID would not clear a bunch of NOx messages.
P2BAE-00, P2BAE-02, P2BAF-00
Cleaned NOx Sensor. Drive/try to clear still no joy...

I was running out of miles, so I took it to a new Indie shop... $3,500 later...
New SCR Converter(CAT), Pig nozzle 'professionally' cleaned. NOx Sensor Professionally cleaned.
Emissions Software updated
Oil and Filter Changed, 3L of PigPiss, Rear pinion seal replaced and new Diff fluid...

They said that the car looked like it was driven by a little ol lady and the SCR was plugged up due to short runs and gentle acceleration, etc. Need to give these things the beans now and again!
I guess you drive in sport and let the mileage suffer. Going 77MPH on the highway, this thing barely ticks at 1,800 RPM

I am at 99,270, so calling it the 100K service. Next Oil Change for me will be 105,000

On the upside - I finally got my Tag after almost 2 months! (REG Plate, License plate) I also got the SIM Card for my Merryway Head Unit 2006 L322 HSE LUX 4.4NA Jag V8 Buckingham Blue/Ivory - 'Col Reb'
Rolled Yahtzee Aug 2023 222,222Miles
2016 L405 HSE TD6. Santorini Black over Almond. - 'Donna the Diesel'
Only L405 IN THE KNOWN UNIVERSE with an L494 Shift Lever Fitted!
97K at purchase Sept of 2023

That's not how SCR works - the NOx sensors are not active until after the engine has been running for 20mins, so if there has been lots of short journeys, when there is a long one, the average usage will be exceeded and set an emissions related DTC. I'd be wary of a 'cleaned' NOx sensor, especially the downstream one as the sensing element does age and not react as quickly as it should, leading to 'SCR efficiency' DTC's.
If the catalyst was blocked / restricted, then I'd expect exhaust back pressure DTC's to be set - none of which are mentioned.
If you want to keep the SCR working as intended, do more >20min journeys, more often. They don't have to be high revs, high temperature, just usual driving style - but more of it.

This is great info - thank you!

I tend to save the Oil burner for longer trips and trips with the Mrs.
If I am tooling around with my dogs... I take the L322 4.4 NA Jag. Much better truck!

The weird thing is I had driven to B'ham (Alabama 150ish miles @ 80ish MPH) on Saturday.
Did a few shorter trips around B'ham Saturday afternoon.

Sunday left the hotel, picked up our son for church and the damn thing came on. 20+ mins to church - short hop to brunch, 20+ mins back to his apartment then 2+ hours home.
The PigPiss nozzle was pretty gunked up, but a little time with a wire pick and some warm water and an old toothbrush - looked like new to me. Message went from a 'Quality' message to a 'Dosing' message.

Just could not get the NOx messages to go off.

What is done is done - new catalyst - whether I needed it or not, I guess - I got a 'free' oil change out of it! 2006 L322 HSE LUX 4.4NA Jag V8 Buckingham Blue/Ivory - 'Col Reb'
Rolled Yahtzee Aug 2023 222,222Miles
2016 L405 HSE TD6. Santorini Black over Almond. - 'Donna the Diesel'
Only L405 IN THE KNOWN UNIVERSE with an L494 Shift Lever Fitted!
97K at purchase Sept of 2023

The dosing valve is a fairly precise item - or should be, it's a fast acting solenoid valve behind an engineered venturi. There are three tests - leakage, spray pattern & dosing amount over a specific time period - usually 26-31ml over 60 seconds, anything else, even just 1ml either side is a 'fail'.

Once the SCR countdown is tripped, it'll keep going until diagnostically reset, even if the system is operating fine (it doesn't shut down if the 'efficiency' threshold is breached).

Because it's emissions related, the operating criteria is very 'yes/no', I spent a week on an OEM (Continental) course on the damn stuff, I can't begin to tell you all of the criteria and what if?'s there are, but I do know that over 80% of replaced dosing valves are changed incorrectly and running a forced (manual) regen works wonders on the Cat & NOx sensors as a 'tune-up' although the downstream NOx sensor doesn't benefit as much as it could due to lower temperatures. All that info was imparted by the OEM diagnostic Engineers (proper Engineers, by qualification, not just job title) and has helped me resolve issues many times since.

I have been watching a bunch of videos by O'Rileys (https://www.youtube.com/@ORileysAutos) Auto in Biggleswade... Love the accent, but is that a real place or something from The Hobbit?!?!? at this point, I think y'all are making most of this up as you go... I know, I know... Biggleswade is probably older than my entire country, but still...

It appears that most of this can be solved by keeping your DEF topped up... I am a bit suspect of the sensor values in "Donna" anyway... I was at about 1/2 tank and put 15 gallons of Diesel in her. Window sticker says 23.5 GAL Tank. The math(s) does not add up...

Donna said 8.7ish liters of PigPiss - Add 9.3 Liters... I figured I was just under half full - the ticket says they added 15L!?!!? Was it so bad having a good ol fashioned dip stick? Like a buck worth of tin and 38 seconds to fab...

it is this kind of crap that makes me appreciate Col Reb even more.

I am guessing either Joey or AlGore has a brother that is a PigPiss Farmer - no one in their right mind would think this was a good idea... There have to be kickbacks involved. I am on my 3rd glass of Dewar's and ice. Any minute now, I will be manufacturing DEF. I am going to bottle it in a large plastic container - because you know, climate change... 2006 L322 HSE LUX 4.4NA Jag V8 Buckingham Blue/Ivory - 'Col Reb'
Rolled Yahtzee Aug 2023 222,222Miles
2016 L405 HSE TD6. Santorini Black over Almond. - 'Donna the Diesel'
Only L405 IN THE KNOWN UNIVERSE with an L494 Shift Lever Fitted!
97K at purchase Sept of 2023

The DEF level has to be electronically sensed so the usage level can be monitored (leaks, excessive usage etc.)and low level warnings / no-start countdown will work, beware of 'brimming' the tank as this can lead to problems, especially in cold weather.
Fuel tank levels are difficult to quantify exactly with a saddle tank, so with 'about' half a tank, and possibly the ground sloping away from the filler side, then it wouldn't be too much of a stretch to get 15 gallons in - always assuming the fuel pump calibration is correct and you were actually getting 15 gallons...

You do know that DEF has been made synthetically pretty much since it's inception, don't you?

I do... But where's the fun in that?
Regardless, it still makes me laugh that AdBlue/DEF is for Madre Earth 🌎, but it's packaged in plastic jugs destined for India... Then the ocean... Math(s) don't add up...

1/2 tank and 15gals in was at Buc-ee's in Auburn. The 105 pumps are in a fuelling island of the most beautiful and flattest concrete you ever did see.

I am going to a client near another tomorrow. I will send you a pic.
I'm just afraid of every gauge now... 2006 L322 HSE LUX 4.4NA Jag V8 Buckingham Blue/Ivory - 'Col Reb'
Rolled Yahtzee Aug 2023 222,222Miles
2016 L405 HSE TD6. Santorini Black over Almond. - 'Donna the Diesel'
Only L405 IN THE KNOWN UNIVERSE with an L494 Shift Lever Fitted!
97K at purchase Sept of 2023