On my mission to replace my melted boost gauge hose I noticed the T piece on the hose isnt fitted tight. It sits loose in the chopped OEM hose. Isn't this bad? Shouldn't this be airtight?

I have pushed the hoses right up the T piece but they just slipping back to the position in the video.

And I am right in saying this is "T'd" into something off the inlet manifold? Would that give accurate boost pressure?

 

Needs to be tight, yes.

You can get different sized t-pieces, or wrap it with electrician's tape before pushing it home.

 

I zipped tied all the hoses when I fitted my gauges, you can get small ties from most places.