Losing Boost

[Alilio, Allan]

I am new to owning an Audi and its my first German car so if I seem like I don't know much please bare with me.  Anyway my question is under full throttle I am losing boost.  I am hitting about 1.6 to 1.7 bar then it slowly drops to 1.2   I thought with the chip I should be hitting over 2 bar.  The following mods on the car are K&N cone filter, Hoppen Chip, custom exhaust system.  I hear noise from my K&N filter like a blow off valve.  Its sounds like its releasing the boost as i shift.  I don't know if its suppossed to do that or not.  I have checked all my intercooler piping and they are all intact.

Thanks,

Allan