Sparks pluges problem

[mhd]

Hi EveryBody

I do maping for subaru Ej25 STI , the 3 sparks pluges stopted completly (was HKS 1 STEP Cooler)during mapping I change them to Denso, yesterday after finishing the mapping while I'm testing the antilage the engine start to miss fire at high boost (1.6Bar)
ps: the car was doing over 525HP with 98ron
Does any one have idia why the sprks doing that

Thank' and best regards
M.Olabi