http://www.americansportworks.com/pd...6152/15193.pdf
page 22 is that thing (part # 14762 AIR INJECTION in to MUFFLER ). I was doing some reading and I think this is what it does.
The air injection system (AIS) is designed to introduce clean air to the engine exhaust as it exits the exhaust manifold or exhaust headers. Exhaust gases are at their hottest as they leave the combustion chambers. Introducing oxygen to the exhaust at this point allows continued burning of the fuel mixture as it travels down the exhaust system and ultimately out the tailpipe.
Got some info on it here.
http://www.smogtips.com/air.cfm
I think it is suppose to help burn the fuel more for cleaner emissions.
So I am guessing I goes from your air box (maybe in to exhaust pipe)
I am also thinking you can probably get rid of it some how and it will probably help performance maybe.