I have had a miss under load above 5000 rpms. I changed and cleaned the air cleaner (K&N) and it seems a little better. I wonder about fuel pressure. It seems to starve out when really putting your foot in it. Suggestions?
Check fuel rail pressure? Should be 45.6 to 50.1 PSI sitting static. Also, a fuel filter that is partially stopped up will check out ok in a static pressure test but will not flow enough to keep the pressure up high so the injectors will not drop out. At full throttle, this will show up as a miss fire as you have mentioned. Not saying this is it, but I would look in that direction as well as plug wires breaking down.