Nox sensor

[Denny 123]

Hi, my 65 plate C220 bluetec with only 40,000 miles, was recalled for a software update and possible replacement of the nox sensor.
on getting the car back, the following day the engine management light came on. I took the car back, only to be told it’s not the work carried out by the dealer, and told me it would be in excess of £700 to rectify this. I feel I am being conned.the engine-management light has never come on before. Anyone else had this problem?

 

[Blobcat]

Hello and welcome

Have a search on the forum, your experience is far from uncommon…

 

[Botus]

NOx Sensor

AA has confirmed that NOx sensor is faulty. My car is C220d Reg 2016. 39k km. Can NOx sensors be replaced as part of recall? No extended warranty. If anyone who had similar problem & resolved it without spending too much to money. Appreciate if you share how it got resolved.

forums.mercedesclub.org.uk

amongst many others...

 

[malcolm E53 AMG]

As above, it’s quite common unfortunately, it would appear that the emissions update changes the fuel mixture to outside the existing Nox sensor parameters hence the engine management light coming on. The only resolution is an updated Nox sensor at the price quoted. A member on here would only agree to the update being done if the dealer signed an agreement that if the engine management light came on after the update the dealer would repair at their cost.... you can guess the rest.

I’d fight it tooth and nail you have plenty of evidence regarding what others have experienced both on the forum and the internet in general if you do a search.