Civic Hx-T

Alright, I don't know where it came from but I suspect that it is because:

When I take off the intake and then give it gas, there's no bogging or anything.

Also, if I put my palm over the intake manifold's opening... the car doesn't cut off... Now I thought it was supposed to die if you do that but I could be completely wrong... correct me if I am.

When I give it gas with the intake on, it bogs down and there's a very loud HISSING sound... it's like a stuttering hiss.

The car does not idle funny at all... it idles very normal. I thought when you had a vaccuum leak, the idle surges up and down. This is the only reason I'm guessing it might not be a leak.

I can't seem to pinpoint where the noise is coming from, but I know it's toward the firewall and further down beneath the intake manifold.

Has anyone ever experienced this? I did a search on VACCUUM LEAKS and it didn't bring up too much... other than how to use Carb Cleaner to find them.