Not sure if the title makes any since. So I have a 91 da integra with a obd0 engine harness with a jumper into a s100 obd1 ecu and dizzy.however I do not like the wires it takes to hook up vtec and all that I want it to look nice.so my questions is can I just use a obd1 engine harness or is the body plug’s different or somthing along those lines. I have Honda parts galore at my house so finding stuff would be easy but I just want to know if it’ll work.

 

Just took a peak at the car and it has a circle body harness plug and the civic has square grey ones I’m pretty sure do they make an adapter to this does the civic engine harness even go into the body? I can’t remember

 

No, you cannot use the OBD-1 engine harness in place of your OBD-0 engine harness. However, you CAN open up the tape/loom on your original engine harness and add any extra wiring necessary to operate your engine (like the VTEC wires you mentioned above) and then re-tape the loom so that it appears clean and original.