OK. Thanks for your patients.
After replacing several vacuum lines, the IC hose at the passenger side was popped off. So that was the culprit. I pushed it back in and put the metal clip.
Test drove with the Stage1 tune. It seemed that the power is back and I'm elated
Alas, drove around town about 40 miles. I saw the 'actual' boost is lower by 5psi than the 'target'. Still much better than hose popped off.
Came home and got the INPA connected. It still gets 30ff code, 2 times.
So, so far, I've tested vacuum status with SunPro hand-pump vac gauge of the following - waste gates, vacuum lines, diverter valves. They are all good.
I'm trying to test the solenoids now. Any good ways to test its functionality???