Ocassionally when I come to a stop the idle will drop so low it will stall. I have recently replaced the plugs to see if that was the problem. It had the Bosch DC before and now it has the DCO's, what is the difference between the two plugs?

Not too sure what the difference is.

I am assuming that you are still having the same problem.

I suggest getting new distributor, rotor, and wires. I am pretty sure that it will solve your problem. However, if you don't want to spend that much money at one time start with the distributor and rotor.

Vin

300E - Idle
 

You might want check your aux by-pass valve also. This unit controls idle speed by by passing the air flowmeter. These units can lock up if dirt enters the intake .

Compare the electrodes of both plugs. One is slightly wider than the other.

Mike Murrell
'91 300-SEL