Header install troubles

[RipShift]

nothing on my car is as easy as it should be. Its a 91 NIssan 240sx. Im trying to install an OBX header but its giving me fits. I've got my stock manifold out of it but now I have complications. There are 3 things connected to the manifold, egr, O2 sensor and one other thing I dont know. My issue is with this one. Its the farthest down the manifold of the 3. My question is basically what is it and can I cap it off? It connects to a box that sits right where the turbo would be on an SR powered S13. It looks like it just takes in air from the intake and directs it to the exhaust -which it doesnt do anymore anyway since I have an aftermarket intake that doesnt connect to it. It does have a couple of vaccuum lines and an electrical connection of some sort going to it. In a nutshell I had to cut that pipe off with a sawsall because it was completely rusted to the manifold, and i mean all-one-piece-no-chance-of-ever-separating-them rusted solid. And since it seems that 23mm fittings are impossible to get in my area, I want to just cap the thing off and call it good. I just want to know if my car will run like crap afterword. Im not worried about emissions, I live in MO. Thanks for your help, please let me know if im not being clear enough.

[NISTECH]

cap it off. that is your air injection for smog. it only pumps air into the exhaust when the car is warming up. other wise it does nothing. It is designed and there to help the cat get hotter quicker so it will reduce emissions sooner. cap off the port on the header, remove the box and all its pipeing near the air box, remove the solonid[electrical connection] and the vaccum lines leading to the intake manifold. cap off the 2 tubes the vaccum lines are connected to under the throttle body. NICE AND CLEAN.

[RipShift]

thanks Nistech

[wilfonzo]

you can rip that damn egr off too, that pipe is a pain in the *** to get back threaded on the header.