Trying to hunt down no boost issue on my n18 r56 MCS and noticed there is a pipe (red arrow on the picture below) on the intake manifold that doesn't have anything connecting to it. Any idea what it might be?

 

It’s a blank connection used in different markets. If you try to stick a pencil in there, you’ll see it’s blocked off.

 

I already tried and it is indeed blocked but wanted to be sure.
Getting 2C57 and half check engine light around 3k RPM and higher load and I'm looking for other potential issues before addressing the wastegate.
I did however stick a cheap borescope through pre-cat o2 sensor hole but didn't have handheld vacuum pump to close it with actuator.

Last thing that's done to the engine was chain replacement so I'm thinking there might be a valve cover leak that's causing this. Trying to refrain from buying parts such as pressure converter if that's not the issue.

 

2C57 is usually the diverter valve. I would pull it from the turbo, and inspect the diaphragm for any holes or tears. If the diverter valve passes that inspection, might pick up a cheap vacuum tester and check the waste gate.

 

Diverter valve was replaced month ago but I've pulled it off nevertheless and checked, visually it looks ok. Not sure how hard the spring is supposed to be, it's quite easy to push it by hand.
Is there a way to test valve cover sealing with manual vacuum pump?
I guess pressure converter could be tested by pulling it off the car and engaging solenoid connecting it directly to battery and applying vacuum.

Here is the borescope video of wastegate amount of play it has when jiggling the actuator pushrod by hand, doesn't look like it would affect the sealing.