Empty Box

anyone know what the strange plastic box attached to 197 the induction system is for? it has an entry (part of induction trunking) but no exit?
 
It's a resonator box, it's designed by NVH to reduce certain pressure waves that cause certain frequencies to excite, so they wanted to reduce or remove these (like loud booming at certain RPM etc).
 
I pulled mine out while I was sorting the radiator fan out - Didn't put it back, I expected it to be a little louder but sadly didn't make a discernable difference.