I am in the middle of installing my IPD Plenum and Carbon Y-pipe.

When removing the stock plenum, there are 4 vacuum lines. One is large andn has a one-way check valve. The other 3 all have similar sized ports. When I removed the middle one, it steps down to a tiny hard vaccum line. After I disconnected this hose, I grabbed it and the tiny hard end was loose and did not appear to be attached to anything.

Is there a breather on the plenum that goes to atmosphere? If so, even though its a small line, wouldn't this cause a boost leak?

 

if this is the case u had prior vac leak. the small hose probably goes to your FPR which is on the right side. back track it . good luck

there is no breather coming from the ipd

 

Thanks, it probably broke when I was removing the stock plenum.

It's hard to get at the lines on the back without pulling and putting some tension on the lines. The one that appears to go to nowhere is a tiny hard/brittle hose, so I suspect it's easy to break if pulled on.