Perhaps the dumbest dpfi-mpfi question ever
 

Here it is, really, really, dumb *** question, brace yourself:
I have a d15z1 (vx engine) complete with almost the entire engine bay harness, the p07 ecu, an obd0 to obd1 conversion harness, and an mpfi fuel injector resistor box, going into 89 dx. The question is, other than wiring the resistor box, what other wiring conversions are needed? If I'm using the proper ecu, then I should not need to repin/splice any wires at that point. And the conversion harness should make the connection to the ecu a piece of cake, right? Enlighten me to why I will need to do all of these wiring changes I have seen on-line because it seems as though they all relate to converting dpfi to mpfi AND using the ecu that came with the dpfi engine/chassis.

For the obd conversion you have to add 4 wires to the obd 0 ecu connector plugs. 2 wires for the extra injectors and 2 for the distributor. You dont need a resistor box for the d15z1, obd1 injectors need 12volts for power. The vx engine harness is pretty much useless (except for the sensor connectors), you cant plug it into the dx chassis. For a honda swap you always modify the original engine harness that came with the car. So you need to add vtec, egr, 5 wire o2, and the egr box to the obd1 conversion harness. If you dont add all of these you will get a check engine light.