Did you take the donut gasket off the o2 housing? Cause there is def a donut gasket on that downpipe.

 

Yeah, it wont fit with 2 donut gaskets on there :P

I've used both type's on my 9 and reused my 8dp with a 9 turbo same o2 housing.

Take the donut gasket Out of that downpipe, leave the one on the o2 housing. see if that works.