A couple less *&^%#! vacuum lines
 

While I was reading some of the Guides over at the UK Supra site, I noticed the Guide author had apparently removed several vacuum lines, and installed a bypass (ignore his red arrow and look in lower right) . Always being in favor of simplification, can anyone tell me what this is about, and if there are any negatives of following suit?

http://images49.fotki.com/v1495/phot.../vacuum-vi.jpg

I remember reading something about this but I cant remember what it does or doesn't do. I want to see the outcome of this also. Seems like it went to a sensor or something that is needed for emissions...