O.k. I have a 95 GSR in my 93 Si Hatch. I was running a Mugen chipped reprogrammed computer in my car for a while until I found a OBD1 GSR ecu. When I plug the GSR ecu in, I get an Electronic Load Detector code which I didnt get before. I plugged in the other ecu once again and it never came back on. Any ideas? Oh by the way, I also tried this GSR ecu in someone elses car but the engine light doesnt come on!!

 

did you reset the ecu when you plug in the obd1 gs-r ecu?
if its the load sensor you need to get a whole new fuse box by the battery.