So long story short I have a b18a1 inside my 96 integra & I'm deciding to swap the whole motor & tranny & just put everything original back in , if I decide to be a new wiring harness or used do I need to find out the obd of the engine or of the ecu. I'm kinda new to all this stuff so please take it easy Honda brothers

 

get the harness that matches the obd of the motor, from what I have read/researched the plugs at the shock tower did not change between 94-01, what changed was the plugs on the motor side, for example injectors alt, etc...