Strange RPM/Boost cut GT3071 AAN S4.

[rwilthil]

Jepp :-).

No difference cold or hot.. I will put aside some hours next week to do some further investigating.
Replace the coils among other things.

[rwilthil]

Well, did some investigating.
Replaced coilpack, no difference..
Replaced MAF, no difference..
Replaced MAP sensor, no difference..

Took away the airbox and just had the MAF connected directly. Some interesting results. Boost now started to drop around 6200 rpm. Kept the throttle down and the boost goes to zero but engine still creeps up the rev (slowly..).

So, it was actually the silicone inlet hose that collapsed by the high vacuum during high boost.

[rwilthil]

Even tried to take away the knock sensors, but no changes offcource!