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Alright. I've been digging through threads for a while now. Talked to local guys about a bunch of things and done a bunch of my own research. I mostly know the answer to this entire question but there's a couple things that have me incredibly confused.

SO my brother(who is not mechanically inclined at all and doesn't listen to me although I've been doing this kind of **** for years. Decade long tech so far, EVO Fein.) blew up his d17a1(non vtec) in his ex civic (mt) he ended up getting a d17a2(vtec obvi), the engine harness, and ecu from some kid he knows. the harness and ecu came out of a 03 civic ex with the a2. Longish story shortish, the car is running I did a few chip swaps this that and the other great. the issue I'm having is the engine harness has ONE 4 wires 02 sensor connector (harness side) which seems to be for the downstream sensor. NOW i was going to just wire in the upstream sensor to the ecu from the 02 civic which has two 4 wire connectors for the 02's. i didn't realize that the 03 ex allegedly has a AFR wideband sensor for the upstream on a 5 wire connector. If that's the case fine, i can get the pig tail for the 5 wire and make it work yada yada. HOWEVER. the car the harness and ecu came from (03 civic ex with the d17a2) has two four wire connectors as well except on of them isn't apart of the engine harness its apart of the body harness on the firewall. Now when I was trying to figure everything out i came across the "sub wire" harness. I don't know if he was missing that and made two 4 wire 02's work or what. Also the kid supposedly said the harness OR ecu was JDM, he wasn't sure and I'm not either.. However from what I've found is the ecu is not a JDM ecu. I can give that ecu part number if needed. I'm mostly concerned as to which style sensor i should wire to the harness. I can do either that's not the issue i just don't know which one the ecu actually needs. Or am i just missing something completely here... I've found to much conflicting info on the two. TIA I can upload pictures if need be once i figure out how to do that on here.

 
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So looking a little more into it it seems the ecu might be out of a 04/05 that uses the wideband sensor instead of the narrowband....

 
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Yeah should just be 04-05 for the 5 wire.
the downstream 02 sensor on the a2 engine comes out under the car by the shifter. You can probably just add pins to the ecu harness and run your wires.