return boost actuator hose

What does this hose do? Im thinking about purchasing another mr2 and the only problem with this one is it doesnt have the return boost actuator hose, the guy says its not an important part and costs about 7 bucks from the dealership, so Im just wondering what it does?

What? *scratches head*

There is a wastegate actuator, but it does not have a "return boost" line.

There is a recirculation pipe needed for the OEM BPV (by pass vale), but it is not an actuator.

I can't imagine what he is talking about.