i have a 2009 a3 . and am looking to install my boost gauge and i have run it thru the fire wall but have not been able to find a place to t off for the boost gauge line---i have tried a few shops and no one can tel me anything its a 2.0T TFSI- 6speed Stronic - APR stage 1. AND they only place i was told it can be done was looking to charge $250 for the setup. deffff not payin that much wen the gauge was 40 bux.

HELPPPPP PLSSSSSS

 

I just got an A3 so I'm not too familiar with the engine yet. When I installed a boost gauge on my Mazdaspeed3, I T'd off of the line that comes out of the bypass valve. The install was pretty easy. The hardest part was finding the right fuse to tap into. You also want to be careful where you put your boost sensor and make sure it's protected from water. I'm not sure about the specifics for the A3 but I hope this helps.

 

I just installed my neuspeed p-flo and was hoping to be able to see where to tap for boost. I still can't even find the damn bypass valve. I can sure hear it now though. I'd appreciat a how to on this as well.

 

the reason your boost guage was $40 was becuase it didnt come with everything you need. you need an adapter that plugs into the pcv hose that comes off the manifold. you can find them on pretty much any website that sells anything vw/audi related.
the bypass valve is located on the turbo, in the back left corner of the engine bay.