Failed spark plug wires and/or ignition coils can cause intermittent misfires (rough running); the Check Engine Light may also illuminate. Diagnoses of the ignition system will be necessary to determine which components are at fault.Google+
Car Problem Reports
Mercedes-Benz C230 Bad Spark Plug Wires/Ignition Coils May Cause Misfires and Possible CEL
Mercedes-Benz C230 Problem
Average Mileage: 74,400 mi (15,200 mi - 113,000 mi)
Visitor, 2000 Mercedes-Benz C230, 95,000 mi
changed spark plugs and wires still experiencing misfires and loss of power. no solution yet.