E 220 CDI ENGINE PROBLEM, PLEASE HELP

[Mihai Bivol]

Hi everyone. Started to notice the high MPG and loss of power on my 08 e220 cdi. Bought a Bluetooth OBD scanner and the next codes appeared :

P206D

P20B6

P2251.
In anyone experienced that, please give me an advice on what to do next or what might be the problem.
Thanks !!

 

[onefortheroad]

o2 sensor is at fault or broken .