doing an itr swap into a 99 ek which harness do i use
stock,sir or itr
99 si stock

 

I modify the harness that came with the car to reach their respective sensors and I add a sub harness for the new wiring (VTEC solenoid, VTEC oil pressure, knock sensor).

If you can find a harness for a 99 SiR, that might save you some wiring, but there could be wiring differences at the ECU and a few other sensors on the firewall depending on the model.