Oxygen sensor for GSR swapped civic.

Need to change my oxygen sensor, its a gsr motor in an eg. Do I use the integra one or civic one. I didn’t do the swap so I have no idea if it’s the civic harness or integra. It’s a 4 wire oxygen sensor if that makes any difference. They’re showing up as two different sensor part numbers.

Additionally, I’m putting an aftermarket cat on it, does the o2 sensor have to go into the cat or can it go on my header?

you can use any civic or integra 4-wire o2 sensor, theyre all the same. i used my stock dx 4 wire o2 sensor for my ls swap

and stock, at least on my ls and every d-block ive ever owned, it goes into the downpipe, before the cat. it may be diffrent for a gsr, but i doubt it

Thanks, I figured as much but the part numbers came up different for them so I figured I’d ask. This is an aftermarket header designed to replace the cat, but I want to put a high flow cat on it, so I’ll just put the o2 sensor in the header and hope for the best.