Well im not sure about where the o2 bung is on your integra, but i know if you had to modify it what you would need to do.

You would not only have to drill a hole in the correct place, but you would have to take it to a muffler shop that will be able to weld an o2 bung where the hole is, pretty much a large nut that the o2 sensor will screw into.

So its not just drilling a hole and sliding in the o2 sensor like the guy might have made it out to be.

You might want to just buy one for your year integra. I bought a new dc 4-2-1 header off ebay shipped for like $270, thats pretty cheap.

I can pm you the ebay screen name from the place i bought it from if you want.