checked your fuel filter lately? mine was blocked and was causing mine 2 lean out on dyno aswell. replaced pump first cause it was a bit noisey, but later decided to pull fuel filter off and i couldnt even blow thru it. problem fixed after that. also try a different CAS. mates 32 was making 450rwhp then next run 350 then 370 etc, replaced with a dif CAS and problem solved.