Nox sensor fault and adblue malfunction

[Sarah9]

Hi,
I have a 2017 Vito 2.2. The engine management light come on and it was Nox sensor which Mercedes replace under warranty. Its been off road over lockdown and got it back on the road and the light came back on again!
Warranty expired! So took it to garage said it was Nox sensor and cleared the code. It was ok for a week and I filled the adblue up and now it’s saying ‘adblue malfunction in op in xxxx miles see manual’ with no engine management light on. Put it back in computer and no faults!!
Could it be the Nox sensor still? Anyone had the same dash warning?
TIA

 

[Dodipops]

I had an adblue malfunction with a faulty nox sensor, the sensor wasn’t actually faulty, it turned out to be a bit of corrosion on the rear nox sensor wiring plug.
It was a viano 2.2

 

[grober]

If the vehicle has been inactive the urea solution [adblue] may have crystalised and partially blocked / disrupted the dosing system?

The dos and don’ts of using AdBlue

AdBlue: if you are driving one of the latest clean emission Euro6 diesel cars, no doubt you’ve already topped up the special tank on your new car with the additive.

www.fleetalliance.co.uk

 

[tombell]

Bought a 62 Plate Merc ML at the beginning of May. A week ago I got message something like "1,700 miles before AdBlue runs out". I filled AdBlue to the brim. EML light still on. Tried all the tricks on the web to turn it off. No Go. Next day "600 miles engine won't restart". Took it to MB Oxford today. They are getting 2 Nox sensors for the end of the week. They want £1,871.52. and will have to remove exhaust. 3.8 hours
Does anyone have the part numbers for the nox sensors and the adblue tank
Mercedes want £1800+ to sort this problem

 

[tombell]

I haven't used one but I think tat this £300 gadget overrides the EML message that says "You won't be able to restart in xxx miles
I guess it would be handy to keep in the car to keep you on the road.
Just wondered if anyone has tried this gadget............It's on YOU TUBE