Engine check light

[Steve Taxi]

2017 E220d I have a yellow engine light on and off more on than off, had the faults read and wondered if I could fix it myself
Codes
P300642
P300646
P300648
P3007C8
P300647
all relating to nox sensor 2 bank 1 the car is running fine but I would like to put the warning off as I'm thinking of selling the car

 

[LostKiwi]

NOx sensor issues are not straightforward.
Often when you change the sensor it needs a software update as well.

 

[Steve Taxi]

Thanks for that but the last time I had a free software update on an S Class it cost me £500 and had to sell it as it would only do 30mpg after

 

[LostKiwi]

I don't think you understood.
The new sensor won't work properly without the update.

 

[Steve Taxi]

okay thanks off to the dealer then