I have a 2002 Audi TT225 Quattro. I am attempting to install a boost gauge however I am having problem finding a passageway through the firewall. I have consulted numerous online guides including CincyTTs but I can't locate this grommet by the brake booster. Is it different on the Quattro models.

 

Try taking the engine cover off and using a flash light. I have very little mechanical experience and found it very quickly from reading CincyTT's posts.

I don't know if this will help but follow the hose coming out of your manifold. It connects right next to where that plug is on the firewall. Also imagine the divider wallbetween the engine and the steering wheel. It is above the pedals and below the top of the dash board in line with the steering column.

 

Look directly behind your diverter valve on the firewall, you should see this black rubber circle. This is where you should send the tubing through.

 

I was going to say the same about the diverter valve but didn't know if he would know where that is. I knew because I have a big shiny Forge DV to reference. AlsoI wanted to say that I cut down a wire hanger (about 18")to poke through the plug. I taped an exacto knife blade to it and....... it poked through like butter.

 

you can see the plug where my dv use to be next to my thumb and the fat hose is where the pvc use to be.



And yes a knife or scissors to make a little hole will make it easy to slide it through with a wire hanger (12-18")

 

This is the best how to guide there is:

http://public.fotki.com/BlueTTop/mod...st_gauge2.html

I too found it a little difficult to find at first until I found this link. The heat shielding slightly blocks it but it is just to the left of the brake booster and once you find it it's very obvious.