Hi i have a 96 civic with a 98 b18c1. I know i have 2 o2 sensors one before and one after the cat. Now, is the primary one the one before the cat. and the secondary after?? Probably by the sounds of my question but i just want to make sure. OK now my next question. On the wiring harness how do i know which of the two plugs is for the primary or for the secondary?? Are both of the plugs some where in the engine bay??