You can not use the jdm harness. The stock in-car harness has the wires for vtec and everything would work out fine if you plugged in a usdm h22a harness, use one if you can. You could use the h23a harness here is what you do:

vtec solenoid is a one wire plug on the engine harness. On the car harness there is a single green/yellow wire that is its own seperate plug that is capped off. It is located by the passenger side shock tower. Run the vtec solenoid wire there.

vtec oil pressure switch. Two wires on the engine harness. One is signal the other is ground. The ground will be black and the other should be blue. The signal wire is present on the car harness. On one of the large plugs by the shock tower already has this wire run to the correct spot at the ecu. Find it by matching the engine harness plug and the car harness plug together there will be a pinout on the engine harness that is plugged off and on the car harness side there is a wire that runs to the ecu. Run the signal wire to this pinout. For the back wire run it to thermostat ground or any other good ground.

You can use the vtec solenoid and vtec oil pressure plugs off the jdm harness.