Does anyone know what the two vacuum lines on a 96 opti do? Are they just for venting, or does it actually use vacuum for advance? Also, does anyone know which vacuum port to tap into for a boost gauge.

 

Vacuum lines to opti keep moisture out. As far as boost gauge you can hook up to any of the vacuum lines going into the intake. You can use a T fitting. I took out one of the factory fittings and hooked mine up directly to the manifold.

 

The lines are just to draw filtered air through the unit. All timing is done by the pcm.

AFAIK, any vacuum port on the intake will give you the same reading for a gauge.

 

thanks guys, that's what I thought, just making sure.