Sorry to be a pain in your side about this. but is it a P1K5 or a P1k3 ? I think i still have one that went to my P1K5 Id have to look.
If u need one for a 3 I think the mounting is different
Well i dont know does extension pipe = head pipe in my past after market exhaust you had to use your head pipe over.So most would not have head pipe and does head pipe have the o2 senser.I think i would be good with muffler only.