I know how to install so thats not my question but I recently boughta GSX and it already had a digital air/fuel gauge installed looks like an NGK, but anyways I was looking at the vaccum line I have to tap into and it already has a "T" into it. I assume for the air/fuel gauge. So my question is with that already tapped into it will it throw of my reading for the boost gauge if I use the same line? Also is there another line I could use instead if this would be a problem?

 

It would be fine to use the T fitting you already have...

 

You need to find out where that, already tapped, line goes bud. It does not go to the air/fuel gauge. That gets its readings from the front o2 via ECU.

 

I know I'm still learning but it didnt make sense that a a/f gauge would be going to a vaccum line. I followed the line and it went no where. I just bought the car so I guess he had gauges already hooked up so the end of the line just had a clamp on it. Nothing was leaking out of it I just took the clamp off and hooked to my boost gauge. It works fine now.