Originally Posted by westcoaststyle

no, you're not.

The OBD2 engine will go right into your car. The 6th gen Civics had an odd way of doing their engine harness though. The tegs and the 5th gen Civics had all the connections at the strut towers. The 6th gens didn't. You could get an OBD2 GSR engine harness and everything will bolt up/wire up fine in your engine bay. You can then use an OBD1 ECU for the engine on your OBD1 ECU harness that is currently in your car.

Even though the engine and the engine harness is OBD2, the ECU will only look for the OBD1 sensors and not even read the OBD2 stuff. Hope that makes sense.