you need the resistor box... yes you will run way rich if you dont have anything to control the fuel pressure... you can use the VAFC to control this.. also, if you have OBD-1 civic, the DSM injector will plug in, if you have the OBD 2 then you need to replace your injector plugs... i was gonna go this route but decided to save up more money and go for the standalone... prolly AEM EMS....