So i have a 1989 honda civic lx 4dr. in the engine bay resides a 1990 integra ls motor. i am unsure if the wiring harness is from the ls or from the civic. the ecu is from the donor car. the ecu itself has no codes in it. however the check engine light is on brighter then anything. the gauge cluster is origional civic. any idea's. any and all help would be appreciated.