Building a 13B.....Need some help with connector/hoses....

[Booztd 3]

I've got everything assembled back together but im not sure what this actual plug is for, and what these two hoses are for. I was thinking the plug (in red) is for the knock sensor, and the two hoses (in green) are both going to the smaller of the black plastic boxes.

Thanks for the help.....

http://i3.photobucket.com/albums/y96/Booztd3/Tech%20Stuff/DSC03192.jpg