Emissions control failure, starting prevented in 700 Miles

[Mick R 8 R]

Hi
I had the warning 'Emissions control failure, starting prevented in 700 Miles' and flashing UREA light on my dashboard while driving along the motorway in my 2016 C$ grand picasso 1.6HDI.
There is Adblu in the tank and there has been no low adblu warning messages.
Code P20F6 was showing with a friends checker (a Creader VIII) which suggested the Adblu injector fault. There was white crystal on the outside of the injector and a trail of white crystal in the under tray under the engine. I have replaced the injector and cleared the fault codes. The car drives as normal and there are no error codes showing on the system but the Emission control failure and the UREA light are still on the dash (now at 650 miles).
The only other thing I can find from the reader is the EGR monitor bank 1 page shows a status of fail with a test value of 655.22% against a minimum limit of 604.36%, whatever that means.
I have the car booked into the local Citroen dealer for diagnosis but they cant get to it for 2 weeks!, by which time I will be out of miles.

Any advice as to how I get rid of the dreaded countdown very welcome.

Thanks


Mick

[GiveMeABreak]

This fault code generally requires a guided diagnostic that runs tests and advises on solution depending on results. So it may just require a simple reinitialisation of the DeNOx system.

I wouldn't let it run down to zero or it won't start.