Hi Gents

I have a boost problem on my a4 DTM 2.0T

before the car reaches operating Temp 90 the car boost perfectly no problems ,when the needle hits 90 the boost
totally vanishes while driving i notice the needle on the temp Gage goes down between 50 to 90 the boost returns
with vengeance then goes back to 90 boost dies out again

I need to be point in the right direction as 2 audi mechs cant pick up the problem
I am not very clued up on cars

fuel pressure test was done all checked out
stripped the front of the car inspecting for any damaged or cracked pipes all checked perfect
fuel filter replaced
diagnostic picked up P0100 code mass air flow no signal/communication replaced with new one still picks up same code
mech fixed metal pipe rubber i think its valve breather pipe sits near the coils drivers side no fault codes after that but the
car still losses boost

De cat 76mm
k04 turbo
software remap done at audi Uitenhage
R8 racing coils
forged DV