Ive read quite a few of the threads on Nox sensors but still don’t know what to do......I’ve just bought my first Mercedes a 2015 E350 coupe. Only had it 2 weeks. On the day we picked up the car the EML came on, MB couldn’t get the car in for a week so we took it to an independent MB specialist who diagnosed a NoX sensor issue. The dealer we bought the car off arranged for it to go to a independant MB specialist who found a perished seal on the exhaust near to the intercooler. A week later EML came on again and came back A non-specific Nox sensor fault. They changed the adblue and light went off then back on again! Car then went to MB Sheffield by which time the EML has gone off again. They were going to replace the Nox sensor and do software update on a goodwill but can’t do this now as no faults on showing! We are getting car back tomorrow but suspect the light will be back on soon! Any advice please?