Mercedes Benz repair: mercedes c180 coupe 2002, mercedes c180 coupe, auto help

Question
the engine manegment light comes on all the time and the car looses half the power, a local garage done a diognostic and replaced 2 parts ,but cant find anything wrong,and its still the same, avnt gone to merc garage yet, can anyone help,

Answer
Engine management light. Ok lets see. You have a Euro version. But Engine management in the US would be check engine light. What code is being generated by the computer. What computer are they checking your car with?
Let me know
Ralph
Miami Auto Help Inc