Hi,

We have a 1996 C180 Classic, and we too had a similar problem to you, we took our car to the local Merc garage, they foun the the Lamda Sensor was faulty, it cost £90 plus labour and VAT to put it right, I'm now pleased to say that it no longer makes me feel sea sick whilst waiting for the traffic lights to change colour, the miss firing, or loss of power has now been sorted.
I believe it has something to do with the fuel injection system.

Hope this helps

Lisa