got a 2001 CL600 check engine light this afternoon. car is sluggish and has rough idling. OBD II showed p0300, p0303,P0304, P0305,P0306. Car is still starmarked till this december but i really don't trust the only dealer in town after my last service. that P0300 really worries me. i guess it's not simply the plugs. i don't know any good MB mechanic that would service V12's locally (Reading, Pa-one hour west of philly, 2 hr north of Baltimore, 2.5 hrs southwest of NYC). Is plugs diy in these engines? i just changed the plugs and wires for my wife's 02 ML320. could this be O2 sensor or cat converter?