i recently got my muffler installed with custom pipes in 2 1/4. a friend of mine gave me an ex header to put on my d16y7. would it be a direct bolt on? or do i also require another piece to go along with the ex header for it to fit properly? any help appreciated.

 

Well you have two o2 sensors on your exhaust right now. So you will need an extra bung welded in somewhere either on the manifold or on the exhaust. Then just extend the harness. To have a perfect fit you will need to grab up the ex donut gasket and flange that bolts to the header. I ended up using some old chevy donut gasket and it worked, but didn't last long. Glad I went boost.

 

Or you can just get an EX/Si cat, extend the o2 sensor wire, and you're set.