In the Champion “double platinum” manufactured 2004-2012 the little platinum alloy discs will come off and cause random misfires.

NGK irridium plugs have worked well for replacements

You need a clip on ignition wire tester with a computer chip that reads out
burn time, peak kV and min kV

Oscilloscope readout would be even better

I have two KAL KEQ 2969 spark testers in order to compare two cylinders,
but I wish someone would sell an affordable tester that showed an oscilloscope like display.