The ecu is a chipped p28, so it is obd1. I changed the plugs on the distributor and the alternator so that it would be obd1. All the wires are the same they just have different plugs. The reason I had to do those things is because the car that I got the engine from was a 98 ek coupe, so the guy had modified things to work in his obd2 car. All the plugs from my harness worked with the engine. I did not modify my engine harness at all except for the alternator plug. I modified the plugs that were on the distributor, not the ones on the harness. If you have an obd1 alternator and an obd1 distributor then you will not have to modify those. If they are obd2 then you will, or you will have to get obd1 versions.