I installed a 1998 Acura GSR engine in my 1999 Civic HX. It runs great, but the speedometer and the tachometer aren't working. I tried changing out the speed sensor, but that didnt help. I have a Si ECU installed right now. I was told the P72 ECU may fix the problem so i purchased a P72 ECU that was pulled out of a 1998 Acura GSR but one of the harnesses will not plug into it. Perhaps a jumper harness? Any suggestions? thanks

 

you need a obd2a to obd2b conversion harness to use the p72 ecu

did you use your stock engine harness?

 

No, i pulled the harness and ecu out of a honda Si.