Can I put a 2018 BRZ exhaust on my 2013 FR-S?
 

I have an aftermarket header (JDL UEL), so everything from the header back I am interested in swapping out. My FR-S has quite a rusty exhaust from regular winter driving and have some small exhaust leaks all along the way.

I was looking for another healthier OEM exhaust to replace it with.

Someone near me is selling a 2018 BRZ exhaust with low kms, and I'm wondering if I would have any issues bolting it to my FR-S.

Yes. The difference between the years is the axle-back portion (with some aftermarket exhausts supporting both pre- and post-facelift). Since you are replacing everything to the header you should be good.

I did this with a 2017 cat back, works perfectly. I cleaned it and coated it to help stop corrosion

No issues. I put a 2017 exhaust on my 2014. If you're replacing gaskets(which you should be) the front donut gasket is the same across all years, 1st gen at least IIRC - part number 44022AA123. The only difference is the rear axle back gasket. 13 -16 MY's use a 2 hole flange gasket and 2017+ use a compression style o-ring. Part number 44011CA000. I also recommend getting new a spring bolt kit as yours are probably going to be a pain, and possibly destroyed. This is the one I went with. OEM part numbers are in the listing : https://www.ebay.com/itm/363394557705

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