Sorry if this is a stupid question but what does a obd0-obd1 wiring harness do? Is it for using a obdo motor and a obd1 ecu or using a obd1 ecu in a obdo car. Basically I have a obd1 motor (lsvtec) and obd1 ecu (p28) that I want to put in a 1990 Civic. I noticed the connectors werent the same and I'm not sure what I need. Thank you for anwering my stupid question.

 

it plugs in where your stock ecu is and allows you to plug in a obd1 ecu. it is what you need.