For reference in the future I would suggest, on a good running car, to disconnect a vacuum line at idle and watch how the car runs/idles. Try disconnecting a small one and a large one. Disconnecting a large one will make the engine run REAL rough whereas the small ones are not quite as bad but do show up. Also, if you want to get real adventursome disconnect the MAS meter and watch the idle.

I recently resolved a very, very slight "miss" at idle on my E320 and found that I had the plugs gapped too close together.

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Jim