i have a d15b8 in my car right now but im going to be getting a new motor because this one does not run. say i get a d16y8 does that mean i would have to change out my ecu aswell? what all would i need?

 

Your d15b8 motor is a non-vtec cx motor.
You will need an obd1 vtec ecu to run the d16y8.
I would recommend a chipped unit as the d16y8 uses different ignition timing values then the d16z6 (sohc vtec obd1 motor).

Other then that, you might have to make minor wiring modifications to the engine harness depending upon which injectors/distributor/alternator setup you end up using etc.