I'm just curious as to how these systems work and what they do.

 

I don't have my Chilton's with me, but I've read about it before, so I'll try and remember what it said. Basically, under engine braking, the diverter valve on the emissions crap blows air out of your air cleaner so as not to cause backfires and detonation. Sorry this is kind of a vague description, but I couldn't remember the specifics. I do know, however, that the V-6 engines had a different setup than the V-8's (V-6's were more complicated), and that if you still have the emission stuff on the car, it's a good idea to have that thing working.