You've still got leaks in the intake plumbing, and they aren't fixed. Buy new hoses.

This is what happens: The turbo sucks air through the air box and the air mass meter (AMM). It goes into the turbo and gets compressed. ALL of that air is measured by the AMM. Then the compressed air goes out of the turbo to the intercooler, through a hose that can leak. Then out of the intercooler to the intake, through 2 hoses that can leak and a pipe. Then, the intake has a bunch of vacuum hoses that can leak, a manifold gasket that can leak, and the fuel injectors have seals that can leak.

When the engine is idling, it makes vacuum. That means inside the whole intake setup there's negative pressure- any leak makes air get pulled into the intake, and makes it a little lean. No big deal. Under boost, however, those leaks mean pressurized air is blowing out, and not being fed into the engine. But the fuel computer already did it's calculations based on what that AMM saw- so it dumps in fuel, making the mixture go very rich. And it gets worse the more you press on the throttle.

Fix the leaks, it'll be all bettah!
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Rob Bareiss, New London CT ::: Roterande Fläkt Och Drivremmar!