I have a 99' Civic Si coupe, long story, motor destroyed internally, everything else is fine. AEM Cold Air, AEBS int. mani., Hondata Gasket, DC 4-1, Invidia Cat Back. The motor(Long Block with alternator, distributor, power steering pump, fuel rail, injectors, throttle body and VTEC solenoid) I bought to replace it is a JDM 92-95 Civic SiR, obviously OBD-I, not OBD-II like the ecu for the car itself. I've done a ton of different searches on here and cannot definitively find the exact answer i'm looking for anywhere on the web, so I turn to everyone here to either help me with an answer or direct me to a search or person who knows exactly what to do. I've heard that if I swap out the OBD-I parts(sensors, distributor etc.) on the new(well, used but you get the picture) engine with the old(blown) OBD-II parts from the Si that it will run fine without setting off a bunch of codes. I would rather not use those parts from the original Civic Si as they have over 110,000 miles on them and the ones from the replacement engine should be in far better working condition. So if I decide to use all of the parts from the new engine, do I need an entire new ecu along with a harness? Cutting and splicing is an option that is not available to me due to time constraints and lack of labor knowledge. Money is not that big of an option, but I really need the car to be running completely perfect for a long time without problems. Can anyone help me solve this the best way?