Do I need this piece?

I put in my offroad h-pipe in today and while doing it, instead of hooking the smog tube back up, I had the bung welded shut so I can remove all the smog equipment later. So that tube that comes from the engien to the cats, I just pulled out where it connects to the rubber hose inside the engine bay. On the pipe it has a little canister looking thing that's right above the passenger side header. Do i need this or will it be ok as is??

K thanks.. that's what I figured. And yes I definately hear that sound... it sounds like there's a miniature weedwacker inside my engine bay. Time for a short belt to bypass the smog pump. What's the part #??