Ok, long story short, GSR motor in to a '00 ex civic, using the stock engine harness, been modded already (motor was already in car, just got fully built and turbo'd) I am putting the harness back on the motor and there is a 3 wire plug that looks like the speed sensor plug near the drivers side of the motor, what was this for? I can't think of what the hell it plugged into. Thanks guys.

 

CKF sensor most likely.

 

yea, i talked to peter at Rywire and he confirmed that, I knew i didn't need it, it was just bugging the **** out of me as to what it was.....