on a 5th gen prelude primary o2 sensor, out of the 2 whites, a gray, and a black...which would you say is the signal wire. im installing a AFR gauge and EGT gauge in my lude and rather than tear back into the ecu, im hitting the o2 sensor direct. if no one know what wire it is, which pin on the ecu is it? any help here is appreciated

 

ok, got it figured out...everyone get out your pad and pen for some quick inside info...

on your obd2 o2 sensor, the wire colors that go from the o2 sensor and the plug on the main harness dont mean squat. ive checked on 3 other cars and they are all different. why they do this, i havent a clue. anyway, back to my explaination, what you will have to do is look at the wiring on the harness side of the plug, those colors are the ones you need to go by. for most ppl it will be a solid white wire, this is the same wire that goes to the ecu. on my car that white wire was connected to the black wire on the o2 sensor, farked up huh. and if you need the ecu pin location, its D-7 for a 5th gen prelude. not sure about other obd2 vehicles but i think they are pretty much the same as you can swap ecus among different vehicles.

if anyone has anything to add to this, feel free to do so.