2015 C250D W205 NOX sensor replacement

[Nn42day]

Hello everyone
Am not a MB owner but making enquiries on behalf of my niece who has a W205 C250D.

The car has had a number of issues with DPF regen and from time to time goes into limp mode. she has had the issues diagnosed and has had a quote for £1500 for replacement of both NOX sensors that also includes an update to FDOC.

I understand the Nox sensor is a common issue on these, so just wanting to know if the quote is about right, what is a FDOC update? and if it can be done by way of a DIY?

If there are any reputable MB independents in the Manchester (UK) area or the north west to get a second opinion before we shell out on the repair?

Lastly as this seems to be a known issue, is there an underlying cause that is causing the Nox sensors to fail?
Is it due to not enough motorway driving to let the DPF regenerate?

Many thanks in advance

 

[onefortheroad]

If it's an aging car I'd opt for a remapper service and have the ad blue and nox sensor fix applied ,around £250 . Won't cost you ever again.

Early nox sensors and the software running them was total crap by mb standards . Nox sensors are now on I think version 3 .

New nox sensors will need the new software, which is what your update is. ? Or it's possibly the diesel gate scandal update.

You could spend £1500 next week and it could fail again 6 months later , ie ad blue pump ,ad blue spray nozzle ,ad blue tank , another £2000 .

 

[Nn42day]

Many thanks for getting back to me, by a remap, do you mean to delete the nox sensors so that they don’t report further issues or is it a remap to change the performance? will a remap affect the cars fuel efficiency?

Any chance you know of anyone local in the north west who can undertake this work?

Thanks once again

 

[onefortheroad]

Many thanks for getting back to me, by a remap, do you mean to delete the nox sensors so that they don’t report further issues or is it a remap to change the performance? will a remap affect the cars fuel efficiency?

Any chance you know of anyone local in the north west who can undertake this work?

Thanks once again

Have a Google search for ad blue fix in your area. Some offer a stage one remap with ad blue delete whilst the ECU is out . Same cost tbh.