I currently have a d15b1 and I’m planning on switching to a d16y8 was wondering if I need a new wiring harness and ecu. Looking for whatever knowledge you all can tell me.

 

You will need an mpfi conversion for sure, and that should be your first search. You can modify your original harness or buy a custom swap harness, but either way, you will be doing SOME depinning and most likely a lil soldering. The amount of harness modification required will depend on which ecu you choose. You have an obd0 car and an obd2 motor. I think changing your entire car to obd2 is possible, but waaaaay more trouble than it's worth. You will want to choose between obd0 or obd1, the latter having far more tuning options.