During my header install my friend did not pay attention to where the front and rear O2 sensors were located. He plugged the rear O2 sensors in the headers, instead of the front. Is there a way to tell on the wiring harness to ensure the correct O2 sensors are in the correct plug on the wiring harness. I'm not sure that the sensors did not get swapped around on the harness (front and back mixed up). I already know the part numbers on the sensors to tell that they are different...what about the harness? <img src="gr_images/icons/mad.gif" border="0">