you need to use the harness that comes on your civic. just take the harness off of your d15 and modify it. you will have to modify it from throttle body injection to multi-port injection. if you need any help with modifying the harness, just let us know and we can modify it for you and you just plug it up to the car. if you need help, call us at the shop. mahdavi motorsports, 770-923-1550.