Just an update, Subaru have just called me and told me it's "over boosting" .... ?Saying that the previous owner may have messed around with the computer or something. Previous owner being an older gentleman who took pride in saying he'd kept it unmodified, I find it hard to believe - but hey people do lie.

Told me they can't do anything and i'll need to take it somewhere that has a dyno... Pretty unhappy with the service.

Does anybody have any ideas? And also know of anywhere I can take it - Obviously i'm really really not interested in spending thousands and thousands on a tune when all I want is this stupid issue fixed and factory tune kept. I find it hard to believe it has anything but a factory tune and ecu as it behaves pretty much exactly like every other STI i've driven.

Oh god please help. Lol.