Vacuum Leaks, Hissing Noise, Fix

Hi all,

I have a vacuum leak thats causing the codes P0174 and P0171,

I had bought myself a plastic tube to listen to where it was coming from specifically, I'll link in what I purchased,

Mayhems Ultra Clear Tubing V2 3/8" ID 1/2" OD 10/13mm 1 Metre https://amzn.eu/d/9NYE43s

All you have to do is insert the tube into your ear and have a listen to the vacuum lines, if the *hissing* noise you hear starts to become more audible, then that's the part you need to replace,

I suspected the hissing noise was coming from my crankcase breather pipe, the original XK part I think was discontinued, so the part I ordered was AJ81172 fits perfect,

The noise, I'm sure, is quieter but I still have a persisting hissing noise, I listened in again and next to the crankcase pipe there is another vacuum leak, not entirely sure what the part number is so I was hoping someone here knew anything about it, the lines look rather fragile so I'm not sure if its worth replacing with a more robust part, if anyone has any info, that would be a great help,

Kind regards, 

Heres the picture, I've now replaced the plastic line on the right, the plastic thin line in the centre is hissing, does anybody know the part number, or a better replacement part that may be more robust, 

Regards,