I have a obd0 b16 in my crx now, i have bought a header and should be here within the next week, also i bought some o2 bungs to place them properly, where do i have the bungs welded in? Which exhaust runners off the head? 1 and 3? It's hard to tell on my stock exhaust manifold because they are close to the collector from 4 runners to 2. I want to do this the right way and run 2 o2 sensors.