So I've been looking through the FSM for my 1991 N/A and I can't find anything talking about the two air lines coming from the intake piping, they come from the bottom and one routs behind the engine and the other to the secondary injector rail. Also the color plugs that are apart of the engine harness near the CAS. I link they're five of them. Do they relay info about vacuum information back to the ECU? If anyone could tell me what they are and a description that would be awesome.

 

The two hoses you refer to:
-One goes to the BAC, not the secondary injector rail
-The other provides the metered air to the tops of the OMP oil injectors.

The five connectors go to the solenoid rack which meters vacuum to various control points.
The solenoids send no info, rather they are controlled by the ECU.