1st of all, I have no ability to post a picture .. Sorry, I know this would make it 10x easier. I'm putting in a 99 d16y8 into my DX. It was delivered with the wrong exhaust manifold (not attached or bolted to the head). I should have gotten a cast iron manifold with a heat shield & an o2 thread near the middle or base of it. The one they gave me -- a tubular, cast iron header (?) with a heat shield & no O2 sensor bunge. I'm thinking, maybe it's a 5th generation z6, but they have the 'correct' o2 placement, too... I know the b16 has the o2 sensor downstream, but aren't the head bolt patterns different? What could it be?