Ok so the fuel pressure regulator has 3 things on it. The first one goes into the fuel rail and the other one is a return line from the fuel rail. Well, the last tubing goes into the intake manifold and I have no idea what the heck it does. Any suggestions? Is this tubing for our cold start Injectors. Kinda like priming your engine?

i think the last tube is a vaccuum line to tell the fmu how much fuel pressure to allow.

Thats what I have been thinking too, but I think it might actually be for the cold start injectors.

There isn't a cold start injector on 20V's.

1in 1 out 1on top for the vac line