this ECU is of the 2.3 litre Accord. Ensure the wiring harness is routed correctly, as some pins may mismatch.
The O2 sensor is always monitored, the emulator is only to block the power feed to injectors and sometimes also to provide a quench ground for the circuit. Without O2 sensor activity of even faulty heater circuit of O2 sensor, the ECU will never allow VTEC, and the car will also run very bad.
Wire up the ECU correctly and completely using proper relays for the main and fuel pump. Then find a DLC and get the electrician to wire it up correctly too, Dont let him nitto tape it. Proper solder joints are required.
Once the entire DLC is wired up, connect a proper OBD2 scan tool and take live O2 data to verify that the O2 is actually working, If its not you will have to buy a brand new sensor, used ones are usually junk. If your ECU is throwing codes for missing catalyst sensor, then you also need a secondary sensor and CAT or get a tuning shop to make you a secondary sensor emulator.