What is this piece on the intake manifold?

[ArlyDude]

I don't have a picture, but it's the small ****** thing about 2 inches behind the TPS on my 97GTS. Mine has a 6" small black rubber tube connected to it which is tied off at the end.

Also, I am getting my fuel pressure checked tomorrow and I have to find out what the High and Low readings are...or something like that. We are hooking something up to the Schrader Valve to read it, and I know I need to know some numbers for it.

Here is a pic, it's not my car, and this car does not seem to have the little ****** on it?

 

[PhoenixGTS]

It is a vacuum port. Well duh that was easy. The hard part is what for. The instructions for re-installing the manual include: "connect the CCV and canister purge hoses to the intake plenum." By a process of elimination from the other instructions regarding vacuum sources that I actually understand, it must be one of these two items. Perhaps one is yours by the throttle position sensor, and the other is the similar port on the passenger rear of the intake.

 

[GR8_ASP]

Here is my 95. It also has the rubber ******. Tha manifold was not changed very much in Gen I/II. Maybe it had a purpose in an earlier year. Or maybe just for testing.