u/Bered3354

Hello everybody, I have a 2015 STI and I’m having trouble because I bought a 3 inch non-resonated mid pipe from remarked, however it won’t bolt up to my car because my downpipe is still stock and my axle back are 2 1/2 inches I believe( see picture. I just wanna make sure I did my measurements right). I’ve been using AI to figure out all the hardware I need however I keep on buying the wrong adapters so I wanted to ask someone who has some knowledge. What are the specific
Adapters do I need to connect my 3 inch remark mid pipe to my 2 1/2 inch (i think) axle back and my stock downpipe to my 3 inch midpipe. Thanks guys