This is a profoundly undocumented item in our cars. It is an example of the "errors and omissions in our incomplete service manual" that I comment on often.

BUT...
YOu are calling it a "vacuum tube". THIS is a vacuum tube"::


What you have there is a vacuum line. IT runs from the Throttle body to the HVAC actuator assembly in the instrument panel, passenger side.

Referring to a plastic tubing as a "vacuum tube" Is very offensive to me. You are forgiven, but only this one time.

For a detailed explanation of how it should be routed, with photos, CLICK HERE:
https://www.crossfireforum.org/forum...tery-tray.html