I have a 2002 E430 it pull code p0304 # 4 clylinder is dead. which would you try first plugs, coil pack or wires?
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As to your specific issue, I would first swap the coil pack to another cylinder. Probably #1
as it's easier to get to.
Reset codes, go driving. If the same code recurs, I'd then swap the ignition wires with the same cylinder as before (treat them gingerly and be sure to maintain polarity!).
Reset codes, go driving. If the same code recurs, I'd replace the plugs in #4
Reset codes, go driving. If the same code recurs, I'd swap the #1
injectors, renewing the seals on them at the same time.