After borrowing my mates spare turbo, I decided to give it a good test to see what condition its in. After the turbo stays on full boost (10psi) for a couple of seconds the turbo completely cuts out and the boost just dies, sounding like its trying to spool but something is stopping it. It's most apparent in gears 1 and 2. I have no idea of what could be causing this. My mods are catback exhaust, de-cat, mushroom style filter, and a forge dump valve. Can anyone shed any light at all??? Thanks Joe