Vacuum line location?

[bobswei]

In the process of changing the AOS on a friends 1999 996, there was one line that appears like it has not been connected to anything. There's a little dust in the hose so seems like it's been this way. It's on a four way connector. Can anyone tell me where it goes or should I just plug it? One photo shows the general area and the other is the hose.
Thanks.

[911monty]

Looks like the vacuum tubing for the SAI system to me. I believe that plastic black and white check valve on the right of your 2nd pic will plug into that tee. The other end will plug into one of the rubber boots on the plenum. Since you are in Cali you will need to have a working SAI system to pass smog. The diagram should help, the check valve can be located anywhere not just as depicted in the diagram.

[bobswei]

I think I figured it out but was curious about any responses. I looked at a handfull of diagrams and there's differences in them. The car I'm working on has a 4 way connector for vacuum (second photo) and another diagram has a 3 way connector (first photo, "G"). The line that's plugging into "H", on this engine, comes from the other side. So, I don't believe I need a 4 way connector, but just a 3 way. The diagram you're showing, shows a 3 way (#21) connector. I know, this engine has been rebuilt so possible for things to have changed from original.
So, I plugged the 4th hose and put it back together. BTW, changing an AOS on a 996 without dropping the motor is a nightmare. Sticking phones in tight places to find the bolts and using mirrors to help out. Never again.
Thanks for the response.