Citroen Peugeot Nox sensor fault P2202 U029D PCB lets take a look inside and explore poor design ?

Quoted a repair bill of up to £2000 from Citroen Stealership and a two week waiting list even to book a diagnostic slot for £150 + vat
AdBlue tank failure ? replacement ? worst case scenerio
Urea light on dashboard and engine light on with no start milage countdown warning
With a very basic code reader I was able to find the error codes
Seen to many people trying to clean these Nox sensors but the location under the vehicle exposed to the elements and seems to be the most common part to go wrong .
In a recent video I uploaded a basic check of the function of the AdBlue injector but saw the Nox sensor and the price of a replacement .
So I took the plunge at home with basic tools to renew the sensor and one week on no faults on car and its running fine
But whats inside that NOX sensor electronic gubbins ? Lets take a look
You can see it looks fine from a distance but get up close and you can see the aluminium salt corrosion of water ingress .
Maybe don't waste your time trying to clean the probe as this sensor has done six years service / 30k miles and not surprised to see the faults within the electronics
Hope its some use to someone ?

[@mondodaftasabrush]

Just a follow up a year on and 10 thousand miles later and we have had no Adblue issues since
The only warning light has been to refill the adblue tank as requested with the 1500 miles countdown.
Added ten litres of good quality adblue from Halfrauds as they store it inside and it's fresh in easy pouches.
Also added a small bottle of anti crystal solution to tank again as further protection.
Those garage forecourts drums out in all weather's and sunlight are prone to crystallise within the solution.
Read so much heartache on Citroen. Forums with owners getting ripped off with new pumps and adblue tanks I had to share and then a few weeks later the problem reappears and they get stung for another expensive repair bill for a nox sensor which is the fault most likely all along.
Our cactus averages 12 thousand miles to 10 litres of adblue when the warning countdown appears
Read so much about people always topping it up so I assume it's got sensor magnets in the fuel cap and keeping a record in the ecu so those motorists whom add a tenner of diesel three times a week might be getting extra squirkts of adblue as we do city driving as well as motorway journeys but brim the tank full every time when it's got just before the fuel warning light comes on