Rear o2 sensor question?

[BLK04]

I just put Mac longtube headers and an off-road prochamber on my 04 cobra. I messed up and only bought one pair of o2 extensions which I'm using on the front sensors. My question is if the rear sensors are turned off, do I even need to bother extending the wires for the rears? Right now I have the rear sensors screwed into the o/r prochamber with the wires zip tied to the tranny mount since they don't reach and no SES lights yet. Thanks

 

[Adroitmustang]

on a legal emissions, basis yes they need to be plugged in.
But if your car is an "off road" vehicle, then no the only purpose your rear 02 sensors serve is monitoring catalyst efficiency, they have no bearing on your air/fuel ratio and will not hinder operation.