Where would I find the wires for the o2 sensor on a 1993 civic ex coupe, it's obd1 so 4 wire o2. Should I just run 4 new wires from the ecu to the o2? I would think it's the stock engine harness since it's a Ex and its got LS vtec.

 

It should be near the front of the engine if you're using the stock harness. See here:




For the LS engine the O2 is relocated to right before the cat, so you may have to extend the O2 using a harness or wiring it up (#25 in the pic):

 

Thanks!
He sent me a video showing me it, it's right after car as you said, I'll take a look at it when I get the car? I figured i should ask about it now so I can already know what to look for.

 

Here's a picture of the bay, I'll try getting another one when possible.