the P72 is for a 1.8l DOHC VTEC Engine so its the wrong ECU for a B20, doesnt matter if its OBDI or OBDII. In this case it doesnt matter what ECU your running as they will both be wrong.

you would want to be running the OBDI ECU with some kind of add-in like Hondata or Neptune and have the ECU mapped to suit the engine.