What would cause a misfire code on cyclendors 4,5,&6. The car ran rough while the check engine lite flashed. After restart the check engine lite went out and the car seems to run fine. I'm thinking I should change the plugs,but I wonder if that will be enough. Maybe plugs and coil packs? Is there a way to check coil packs? Any ideas? 98 E320 4matic.
Thanks in advance
Bill

look for air leaks. try doucheing down the coil packs/ignition wires with a spray bottle while the car is running and look/listen for arcing/misfiring. If the water test does nothing run the engine and start wiggling wire harness looking for chafing/heat damage. then check power to coil packs and resistance on the ground circuit. make sure the charging system is in good order as the ecu and coils need a specific voltage. unlikely all 3 coil packs failed at once, though you can try switching a coil pack from the other bank and see if the misfing cylinder moves to where the coil pack is. the cam sensor on the misfiring bank could also have an intermittent connection or fault.