Two problems related to manifold/header/muffler/tail pipe have been reported for the 2014 Mercedes Benz CLA250. The most recently reported issues are listed below.
Accelerating from an intersection after the light turned green, the engine began chugging and thumping. The check engine light came on immediately and the eco light started flashing . The engine stalled several times. We drove straight to the dealership with the car. At every intersection with a red light, it seemed as though the car would stall again. We did make it to the dealership. They kept it for three days, and determined that it was a defective manifold pressure sensor. This is the second time the manifold pressure sensor has had to be replaced. In the first episode on October 9th, 2014, the car died completely and the message "inoperable" appeared in the message screen. The car had to be towed in that time. Both instances required replacement of the same sensor and an update to the software.
Was driving down the road, the car started hesitating, and lurching repeatedly. I was just able to pull into a parking lot off of the busy street that I had been driving on. Once in the parking lot the engine totally died and a message of "inoperable" appeared on the message screen. This required towing of the car to the dealership. It was determined that the intake manifold pressure sensor was faulty as well as the crankshaft position sensor was faulty. Electrical investigation revealed that a ground stud on the chassis was painted over and not making contact. Update of software, cleaning of contacts, and replacement of sensors resulted in smooth running engine.