Just a quick follow-up on this issue. Last night I swapped coils and plug wires from left to right just to exhaust all (labor only) possibilities. While I was doing that I checked all of the vacuum connections around the intake duct and throttle body. The intake duct seal was not sealing very well nor was the brake booster vacuum line that goes into the intake next to the throttle body. So today I went to the benz dealer and ordered a new intake seal, brake booster vacuum line connector, seal, and fitting. I'll be picking them up tomorrow and installing everything on Friday. Another thing I picked up yesterday was a code reader so I could read and clear my own codes. I've got a feeling that little thing will come in handy with not only this problem but others that are lurking and waiting to spring on me in the future....
Stay tuned and I REALLY appreciate all of the replies. The knowledge on this forum is absolutely priceless!!!
Dale