1995 E320 skipping a beat

[sasjzl]

My 1995 E320 is skipping a beat, has a very slight misfire that does not seem to affect its performance but is really irritating me and making me worry about it worsening. I have already replaced the plugs with the specific Bosch plugs that are required and the coils and plug wires were replaced not very long ago. Maybe 10k miles. It has 214k miles on it. The idle still appears solid but if you put your hand on the top of an open door you will see the misfire in your hand.
I am just wondering what I could look at after the plugs and the coils and wires? Is there a code I might be able to pick up? The check engine light is on already because of an EGR problem that I cannot get right after cleaning out the tiny pipe that goes into the manifold during a head removal job and replacing the egr valve.

Thanks very much,
Jim Lee