Trouble codes and strange fuel range

[Johnpen]

had my W221 for a a few weeks now, it appears the previous owner removed/disabled the engine warning light before I bought it.

I’ve had the issue where it went in to limp home mode by haveing the dpf sensor replaced.

Now I’ve noticed a strange issue with the fuel range where it’s basically acting like a countdown, every few seconds dropping by a mile, even though the economy bar is at 40mpg. Restarting seems to put it back to a higher level. I’ve also noticed the eco light sees to spend most of the time orange rather than green.

Read the codes with cheapo app and got:

Trouble Code(s)
P2201: NOx Sensor - Circuit Range/Performance (Bank 1)
P22A1: NOx Sensor - Circuit High (Bank 1 Sensor 2)
P14B5: No description available
P1535: No description available
P1118: No description available
P1717: No description available
Last Trouble Code(s)
P22A1: NOx Sensor - Circuit High (Bank 1 Sensor 2)
P13AF: No description available
P149D: No description available
P111A: No description available

I cleared the codes and after a few days the nox p2201 and p22a1 returned.

I also think the fuel economy is not great averaging around 20mpg around town. On a run it’s low 40’s which seems ok.

Going to book it in after I get back from a work trip but any ideas?

 

[Johnpen]

By the way it’s a s350 bluetech

 

[w221s350bluetech]

By the way it’s a s350 bluetech

Did you end up finding the problem, I have a similar issues where the car would go into limp mode randomly, when I connect the scanner ( cheap generic OBD II ) it presents the same fault codes as yours, I thought it was the gearbox conductor plate, but when Brought into gearbox specialist they scanned and found no codes for the gearbox and advised to get the Nox sensor replaced.

Its a 2012 W221 LWB 3.0D Bluetech also.