Desulferization of NOx storage Catalytic Comvertor

[Chimfender]

Following an MIL coming on in my 2014 SL350 (R231) I bought a fault code reader (by Foxwell) and it came up with First:
NOx sensor (Cylinder Bank 1) has a malfunction. There is a general electrical fault. This was followed a few days and 100 miles later by:
NOx sensor (Cylinder Bank 2) has a malfunction. There is a general electrical fault.
OK I can deal with this its going into MB shortly. However there is also a message in a separate section under the heading 'Exhaust after treatment' which says:
Desulfurization of Right NOx storage catalytic Convertor - Required
Desulfurization of Left NOx storage catalytic Convertor - Required
Anyone know what this means/entails?

 

[ajlsl600]

If this motor has a pf I think its saying system blocked. cos issues with nox sensors.? Or message is generated by fault in nox sensor system Someone more familiar with yr motor will be along soon.good luck maybe cat convertor blocked /damaged. .

 

[Chimfender]

Thnx for your input, I'll wait for an input hopefully from someone who knows about it.

 

[alexanderfoti]

The second message is erroneous, as the NoX sensors are reporting incorrect information. Once they have been sorted it will go awy.

 

[ajlsl600]

Faulty nox sensors ,that would be a real surprise.......

 

[Chimfender]

Thanks guys it was what I was thinking re the erroneous mssge. It goes in on Monday.

 

[ajlsl600]

Plse advise how that pans out.

 

[Chimfender]

Will do

 

[Chimfender]

Both nox sensors replaced, £1200 done under warranty (not MB).£371 each plus VAT plus labour. Haven’t checked the desulpherization message yet but will do so and get back.

 

[ajlsl600]

Nox sensors are just a rip off.no other way to describe it.
Did they do the updates ref new nox sensors