under the intake manifold there is a black box with a circle plug for two wires. what is dat for? and how do you wire it up? THANKS

 

Sounds like the seconday intake runners (IAB) or butterflies, it goes by many different names, do a search for IAB. I believe there is a difference between OBD1 and OBD2, one triggers with ground, and the other with 12v.

-PHiZ