Leave the vacuum line alone. Dont worry about pulling vacuum lines off or clamping anything, this isnt a MK4 R32
Disconnect the vacuum valve spindle (looks like a piece of wire) which connects to the flapper butterfly valve arm. Vacuum will continue to operate the valve and continues to move the valve spindle which protrudes from the black vacuum unit but the "system" doesnt know you have disconnected this link to the flapper arm in any way.
There are no sensors there.
Wire "Open" the flapper valve itself using some stainless steel wire threaded thru and around the flapper valve arms spindle hole ( where the actuating valve spindle was inserted previous to u removing it from the hole ) and tie the wire around the exhaust pipe in such a way that the butterfly valve cant move from its open position.
Without wiring, it just flops around loose.
Basically I precut a length of Stainless wire that would go thru the tiny hole and also pre bent a small "S" shape kink in the middle of the length of the wire and made this kink sit thru the flapper valve arms tiny hole so the wire could not slide thru of its own accord later and maintains the flapper position. Well the "S" shape was more of a "Z" where the angled part of the Z was vertical instead. You might get the gist of what I mean.
After wrapping the wire around the pipe I twisted the two wire ends around each other with pliers.
Not easy to get in there with your hands but did my MK5 R and its got a good noise all the time now. Deeper thrum at lower revs and good idle sound. Cheap mod really.
No warranty voided, no sensors alerted.
My attempt was prompted by the work this guy did to do his.