I have a 99 Audi a4 quattro (Pics under profile) with auto and i have a boosting problem where it says I'm pushing out 5 psi instead of 11 psi, the standard, and i was looking around and i found out where the tubing i have that i tapped the T into is not even hooked up (Pic) and on my car its a red tube. The weird part is me and my mechanic (Audi tech) were looking and we couldn't find any place off the turbo or anything where the second part would go.

Does anyone know where the vacuum line goes from the front part of the intake manifold?

i thought it would come off the waste-gate controller but it seems like something is there already or maybe that's in the wrong place idk.

and if you have pics that will help too

 

The other end off that should go down to you DV

 

what chocalotstarfish said. Run a line from the intake manifold straight to the diverter valve and take that little T off.

 

The T is probably there to put a vacuum gauge when needed. If it's capped then it can stay, but it's not necessary. It should indeed run to the DV. I have attached the vacuum diagram for my car. You can leave your SAI in if you're not willing to do the work to remove it, but make your vacuum system otherwise the same as this. You can look up the numbers in the Bentley manual download that you can find around as the image is just a modified version of that.

 

Yes, most of the people usually run the gauge off of the other intake manifold nipple on the back side, its cleaner up front with the line directly to the dv. But yeah you can keep the T capped and run the open end by the airbox down to the dv

 

What, an "Audi Tech" doesn't know where the vac line from the IM should go?

oh he should be so FIRED

 

haha well he is older, like way older than me by like 55 years or so and is more familiar with the old ones like Audi 100's and sold me the one i have now cause i traded him a 97 Audi avant 2.8 because he likes it better and i only called him an "Audi tech" cause he's way smarter than i am and most people, not saying you haha.

But anyways i do have a boost/vacuum gauge that i installed a few weeks ago from glowshift and that's when i noticed how low the boost psi was and that's why the T fitting is there and without that gauge i never would of known it had a hole in it and blew off.