Check to see if there is an ECU software problem or upgrade to your 1998 C43.

I had a similar problem with my 2005 G55K.
Dealer replaced a whole bunch of coils, wires, plugs and when floored it still pulled a P0304 code.
Dealer finally discovered that the ECU had to be reflashed with a later version.

What indicates this to me is the fact that if you shut down and restart, it runs properly with no "misfire" ( G55K did the exact same thing )

I have a 1999 C43 and never encountered what the OP has.

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1971 280SL ROADSTER
1988 300CE TWIN TURBO WIDEBODY
1994 E320 CABRIOLET
1999 C43 AMG
2005 G55K AMG
2008 CLK63 AMG BLACK SERIES