Originally Posted by IA Performance
The nipple furthest from the electrical plug goes directly to the intake manifold. The other nipple goes to the metal line under the intake manifold that ultimately goes to the firewall and all the way back to the tank area.
Mine was hooked up with the nipple closest to the plug going to the Manifold, I showed it in my pictures. Not sure why it's the opposite on others but mine is an 05 STI