Problem with my 2003 Porsche Cayenne Turbo

[Yotamre]

i everyone,
I need help with 2 problem that i have with my 2003 Cayenne Turbo.

The first problem is with the turbos, When I accelerator the turbo charge show that does not pass the 0.4 Bar and usually its should go till the 0.8 Bar...
I have Checked and i didn't get any engine failures....

No. 2:
sometime when i start to drive i have hard vibration (feels from the front wheels of the car, look like the front wheels r look).
After a few second its go a way.
Also when i lock the 4X4 i fill and Hear Clicks sound from the Bottom vehicle.

when the transfer case electric motor is disconnected the car drive very smooth

I all ready replaced the following parts:
1. Transfer case
2. front diff
3. 2 front Axle Shaft
And still i have the same problem...

Can anyone give me direction how to solved this 2 problems PLS PLS ???