Whats this vacume hose and where does it go ?

[RSsprint]

I changed my spark plugs yesterday and found it blocked off, anyone know why ?

Ive searched on here (hence the borrowed pic) but still none the wiser.

You will have to click the pic to see it outlined in red.

 

[bmh.01]

Acoustic valve on a Ph2, FPR on a Ph1. Fine that its blocked off.

 

[RSsprint]

Acoustic valve on a Ph2, FPR on a Ph1. Fine that its blocked off.

Thanks for the quick reply