Thanks for the help everone... car is fixed now.
Ended up replacing my turbo and my up pipe and the noise has gone.

As for the boost issue got the restrictor pill in but think i need a ECU reset because i think it is in safe mode.

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MY01 WRX
Turbo-back exhaust
Turbosmart vaccum lines
Turbosmart boost gauge
Turbo Timer

Its a work in progress ;)

IF IN DOUBT FLAT OUT!!