Where do you guys run your vacuum line from your boost gauge to a vaccuum manfiold in a 1996-2000 civic? im assuming there arent any differences between the obd2a and obd2bs. I just need to know if i have to drill my own hole through the firewall, or if there is a hole already where i can run the vac line from my boostgauge to my vac manifold.

 

To run your boost gauge through the firewall, you must first find one of the rubber gromets on the firewall, pull it out, cut the carpet on the inside and then run the vac line through it...i used a gromet in about the center of the firewall that landed me underneath the center of the dash about 6" above the floor. Using a flashlight to shine from the engine side through into the car while it is dark is one of the better methods of finding the hole...

 

There are grommets beneath the battery tray and under the brake master cylinder.

 

I personally ran my wiring for my wideband, water temp gauge, and boost gauge vacuum line through the hole where the cruise control cable went through. Just take a look under the dash, youll find a place.