Is the rear oxygen sensor really unnecessary?

[Corolla Sound]

I got the last piece of my exhaust system today, an OEM resonator pipe for my 1997 Corolla. But, it conveniently does not have the port for the rear oxygen sensor, which sucks, because ive been without a car for 2 weeks now. was hoping to finally get my exhaust on, but I have to exchange it for the right pipe and wait atleast another week or so....Unless there is a way to ignore the rear oxygen sensor? Any suggestions? Ive already sent my request for return (requesting exchange) but could be a couple days before I hear back.

[iToaster]

The check engine light will come on if you disconnect it. However, it's not essential to the operation of the car, all it does is check to see if the catalytic converter is working properly. I would suggest getting the correct pipe to avoid the CEL, but in the meantime you could leave it unplugged.

[Corolla Sound]

I figured that would happen... I might just see if I can reuse my old pipe, little rusty but atleast I have it..

Thanks