Hi
I have a 1993 Mercedes, E220 Automatic transmission.
I don't know how to describe exactly the problem, but what happens is that when i'm in relatively high speed, and I slow down suddenly for a traffic light, or traffic jam, the engine starts breaking up. The engine does not turn off, but when I stop completely and put the gear to N, the engine gets back to normal.

Any idea what might be causing this? I hope it's not a serious probloem
I use unleaded fuel.