OK I think I figured it out

Mine was already hook up when I got the car. So i dont know how to do it. So I took a look at mine and the directions, mine doesnt seem to be hooked up the same as the directions, but take a look at this picture of mine:
http://community.webshots.com/photo/81565168/81565787sBHskG
Now can you see the vacumm block and on the back side of the block the vacumm port all the way to the right side(closest to you going towards the firewall) that one has a tee in it.
If you look closely you can see my boost gauge line running over the white plastic line going towards the passenger fender......my boost gauge line is running over to the passenger fender and then going to a black plastic line which then runs right back to the tee in that vacumm port of the vacumm block(i hope this is making sense to you, cause it aint to me)

so i dont understand why my boost gauge doesnt run right to that vacumm port
Also go out to your car and take a look at the passenger side fender wall...........there should be a cylinderical black plastic canister thing (is it bolted down with a screw) that just sits there up by the ac stuff..........it has a vacumm line going to it............mine wasnt hooked up when i got the car so i took it out.............i think what the person did is ran the boost gauge line to the line that goes to the black POS canister thing and then delete the use of the canister and got a boost reading off that line which runs all the way back to the last vacumm block port on the firewall side.
Now I know my post is 1 FFFFed Up post, but I hope it helps with some ideas..........just trying to help.....Nick
