NOx sensors on 2014 GL350

Question by dkmcconlog posted 4 months 2 weeks ago in GL-Class

Just bought this beauty - check engine light comes on within a day.  Ugh.

Been to indy MB mechanic (excellent - used him for years) and to the local MB Dealer.  Its the NOx sensors - BUT neither of them know if the 'particulate matter sensor' (where the Blue stuff burns up the bad exhaust stuff) is really the problem.

I notice nothing in terms of engine performance - question is this - am I doing damage to the vehicle by continuing to drive it?  Dealer quoted me $2,000 to replace the upstream/downstream sensors, indy mechanic quoted $1400 - but he can NOT update the codes - only MB can.

Anyone have any experience of ideas - I'm desperate.