[way]

Sorry about that, I was talking about on the engine leading to the throttle body. There are two of them side by side and I needed to disconnect them so I can replace the rear main seal. I just can't believe it's supposed to be metal on metal but I can't see any type of o-ring at all in either one. I don't even see any type of residue or anything to think an o-ring was ever there. The parts places seem to list only a fitting, no separate o-ring.

Here's a picture of the type of fitting. It's the one on the left: