Mystery Tube 986 appendix ?
 

Does anyone know what tube #18 circled in the attachment does?

I removed my Throttle Body to clean it and found this tube. It's connected to the main intake tube, but it does not appear to do anything. Its closed on the right end at the nipple. The nipple end fits into a rubber bushing/grommet #17 on the throttle body support bracket. The part number in PET is 996-110-242-00 and its just called "pipe". It looks to me like its just taking space, but Porsche must have put it there for some reason?

Sorta like a human appendix, just there for some long forgotten reason...?

The car is a 1998 2.5 with Tip.http://986forum.com/forums/uploads02...1596230497.jpg

That is the throttle valve tube pipe. It is used on the Tiptronic gearbox. There's a thread a few years back asking about it and the answer suggests it's just used as a sound baffle like #9.

Pressure waves, harmonics, pulses of air molecules at the speed of sound - it was carefully designed to optimize airflow in the intake. If you take it off and de-snorkel you might be able to hear more happy sounds from the intake, but it was put there to make the car run better.
Here's the basics without all the formulas and dictionary words: https://itstillruns.com/air-intake-resonator-do-12156112.html

Thanks for the response and article. Learned something I never knew I never knew today! ;)