Thank goodness that no class B's (to my knowledge) use the VW diesel platform! Hopefully, as well, that Mercedes hasn't been playing any dirty tricks with the Sprinter's emissions.:S
Diesels inherently generate o lot of NOx emissions. Commercial truck diesels and MB sprinters inject DEF (a concentrated solution of urea) into the exhaust system to react with and eliminate the NOx. They shouldn't have the same problems as VW.