Extra vacuum lines under y-pipe

[mattg1.8]

I started doing valve cover gaskets today and when I pulled the y-pipe off I saw two extra steel braided lines with threaded ends, two hard line vacuum lines with nothing attached, and a check valve with a plug over it. Can anyone tell me what these things are all for? I'm experiencing a stumble on very low end throttle when initially letting the clutch out from first. Maybe it's related to a vacuum issue? Any insight is appreciated.

[mattg1.8]

Bump

[jaychen]

first pic goes to turbo inlet pipe.

second pic looks like it goes to air intake if you have 01.5.

two threaded things are egt sensors.

[zillarob]

Jay nailed it.

1st are evap lines that usually go to the inlets. No big deal, but might get a fuel smell in car every now and again.
What inlets do you have? Some dont have a place to run the hoses to.

2nd is late style booster hose and normally hooks to the accordion hose.
This thing is often a prob and many convert to the early style. You have an aftermarket intake? Many dont have a provision for this.

3rd are egt probes that arent egt-ing. Something stupid going on here.
If they arent coded out properly and need to be plugged in, might as well run them. If they are coded out properly, no reason for them to be there.

[mattg1.8]

I am running aftermarket intake and I believe the intake hoses are samco but I'll have to check when I get home. Should I remove that orange plug on that check valve? Do those hard lines up front need to be plugged up? I'm just wondering if these things can be linked to the hesitation/stumble in experiencing.

[zillarob]

I am running aftermarket intake and I believe the intake hoses are samco but I'll have to check when I get home. Should I remove that orange plug on that check valve?

No, leave it plugged.
Even better, convert to the early style. Common for the tee piece in the middle of yours to blow apart and cause big probs.

Do those hard lines up front need to be plugged up?

Id leave them open, but not a big deal either way if your check valves are working.
They should have hoses that run to ports in the inlets on both sides of the engine.


(best pic I could find, but both ends are just out of the pic)