legacy dan

Can anyone help! i have had my legacy turbo for 5 years now & it has bean great until the last month or so. i have done all the starter stuff ie: induction kit, full ss de cat, hks fcd. more recently brand spanking vf34 turbo modded to fit, new up pipe (ss) it ran fine after all the latest stuff untill a month ago over boosting like mad checked every pipe nut bolt etc, all ok i took it to my local rolling road who came back with a very long list of bits: new uprated fuel pump, greddy plugs,air flow meter & new coil packs. the only bits i haven`t done are the coil packs which are on back order with subaru uk. has anyone had this problem before & is it just a case of new coil packs & a quick rolling road session?