One problem related to gas recirculation valve (egr valve) has been reported for the 2013 Mercedes Benz C250. The most recently reported issues are listed below.
While driving to grocery store attempted to accelerate from a stop and vehicle bogged down (decelerated before accelerating) and the violently took off. . Have taken vehicle 8 times to different Mercedes Benz dealerships in the atlanta area only to be told that its the way vehicle is and to live with it. On many occasions while attempting to turn across traffic vehicle just stays in place when accelerator pedal is depressed and then it just bolts wanting to let the rear end loose. Very unsafe characteristic of this car. Regret this purchase tremendously. Also many many complaints about the 2012-2014 C250 and nothing is being done.