2000 E430 misfiring and slight vibration - Help

[Hooykin]

I have a 2000 E430 with 90K miles. A few month ago I started to feel a slight misfire at idle. At idle, after I place the car in drive and start slowly releasing the brake just enough for the car to start moving, the car begins to hesitate and jerk forward about every second or two. Feels like it loses power for that split second that the engine fires a certain spark plug. At regular driving speeds I do not feel anything and the car drives fine no hesitation or misfire. By the way the Check Engine light is NOT on.

I thought it could be a bad plug, so I replaced them and no change. I was thinking it could be an ignition coil or wire?

Has anyone had the same problem? How can I test to see what the problem is?