DS5 2013 156THP - Rocker cover

[Classified]

So i had the car in service for throttle body replacement, and they stated that: there's a "hard" negative presure in the engine / valve is open -> Rocker cover needs to be changed.
Causing high oil consumption.

Without really thinking more of it, i ordered a new rocker cover with seals, part 0248Q2, and i've replaced the old one.
I assume the valve they mean is PCV valve, is the one that can be seen from inside the rocker cover, that has a red rubber like cover?

Then i realized there is a small outlet in the back of the cover, the rocker cover came with a red pull tab in it, which i removed. It felt weird just removing it, so i looked around and read and seen pictures that it should be replaced with a small black plug, which i don't have. Most of the rocker covers available for order don't have the plug, at least shown in the pictures, but some do. I have no idea what that plug is, can't find it in parts catalogue, can't find any numbers for it.
The old cover did not have one either or it has fallen off. Could this be causing negative pressure?
Does the DS5 have this plug / need this plug? Any ideas?

I have not checked the pressure yet after replacing the cover, need to look in on how to do it with diagbox.

The link shows the best pictures of the plug, tho it is for Mini Cooper, but same cover, and that same plug can be seen in some ds5 covers.
https://www.ecstuning.com/b-hamburg-tec ... 6555plug~/

Cheers, and happy new year to everybody!

[xantia_v6]

I have only found a description of the purpose of that plug at https://www.ecstuning.com/b-bremmen-par ... 46555~brp/ which is a bit ambiguous (from the Peugeot/Citroen point of view) but I reached the conclusion that for PSA vehicles, you just remove the red plug and forget about it.

[Classified]

Thank you for looking in at that, and for your reply.
Yea i'm just going to leave it as it is. If it would be an important / real part, it would probably have a number and shown in PSA parts cataloge, and most likely provided with all rocker cover sets, or at least mentioned in repair guides.

Cheers!