Ok, previous owner installed aem fuel rail on my 99 SH. The problem is that
there's one vacumm hose that is not hook up anywere, and I don't know where it goes. This vacumm hose is from the botton of the intake manifold, and it goes up!

 

That's for the IABs, or dual stage intake manifold.

Search for that picture of the H22/H23 vacuum diagram...

 

so is that ok to leave that hose like that? it does not suck air or anything though..

 

If your worried about it you can screw a screw into it to seal it off.

 

i have misfire problem with ma car even though it runs fine idont know y it's throwing code so im just curious if this hose has something to do with it.