Boost issues

[CarPsyco84]

I'm having the same problem with my tsi, It goes to what you have it set at, then around 4500rpm, it starts going up again. Only thing I changed was I made some 2.75" turbo back exhaust. I guess 2.5" down pipes don't usually have issues, but those with 3" ones have lots of issues, so if your boost issue is identical to that, and your making sure its not just somthing simple, your gonna probly need some evo3 exhaust parts, less someone has any bright ideas,
btw, i took a grinder to the waste gate opening to make it bigger, and it helps, but not nearly enough