Changed out the recirc valve for a GFB one after noticing the boost fluctuating when set at high and full throttle. Apparently an evo one fits perfectly as well and they are made to hold more boost so can do that for cheaper if you can find one second hand. Looks like it was definitely the source of the problem as it now holds boost solid all the way through the rev range. Prob now is I hit boost cut in 3rd gear. Kind of expected with the intake and exhaust done. Guessing that was masked as the old one was leaking the boost. So time to take it off to SAS and get the tune done and CAT removed.