i have a 1997 HX civic that came with a d16y5 with vtec e i just put a GSR in it, i bought the conversion harness for OBD2 to OBD1 for the ecu, my question is will the front o2 sensor work with the ecu its a 5 wire one or do i use the back one and do i have to try to figure out how to make a 4 wire o2 sensor work?? Thanks a bunch!!!

 

I'm assuming you're using an OBD1 P72? You will need to convert your engine harness from 5-wire to 4-wire or use a "VTEC" harness instead otherwise you will throw a code. Also if you're converting to OBD1, you don't need 2 O2 sensors anymore. Only 1 required.