HKS EL Header with Cat (33005-AT007) on a 2017+ BRZ?
 

I'm looking at picking up the HKS 33005-AT007 "SUPER MANIFOLD with CATALYZER GT-SPEC for ZN6/ZC6" (4-2-1 equal length header with cat to everyone else...LOL):

https://www.hks-power.co.jp/storage/...cQmsAma3W.jpeg

In the remarks on their product page, it says that "MT vehicles made after 2016, O2 sensor relocations not possible." Not sure what to make of that.

I would note that japanparts.com doesn't list the header for 2016+ BRZ's, only 2012-2015 (maybe because of those remarks; bear in mind also that the Japanese model years are 1 year ahead of ours, so 2012-2015 is our 2013-2016, and their 2016+ is our 2017+), but HKS's own page lists it as for model year "12/04 -", and the compatibility chart shows it working with all manual transmission BRZ's.

Is there some reason related to the O2 sensor(s) that I'm not aware of that this header couldn't work on a 2017+ BRZ? It appears that there's an O2 sensor bung both before and after the cat, so aside from maybe extending wiring, I can't understand why there would be an issue.

...and before anyone comments, yes I KNOW I'll get more power without the cat, and I'll particularly get more mid-range if I went with something with longer runners like the JDL 4-2-1.

I'm considering this option because I would prefer to keep cats in the stock locations, and this appears to be the only option for an equal length header with one (aside from maybe buying the regular HKS 4-2-1 and having the shortest high-flow cat I can find welded in just ahead of the flange, but there is VERY little length available there).

I wouldn't worry about it. I'm sure the O2 sensor is if you planned to relocate it so you don't throw a CEL. If you get a tune flashed at the same time, you will be fine.

As for it having a cat, that will help the rasp and noise. I wouldn't worry it having a cat. Just do it!

Pretty much what I'm thinking. With the tune, it likely wouldn't matter one way or the other. It would be nice if it didn't throw a CEL without disabling it in the tune, but not really a big deal either way.

I had the non-catted HKS headers and I just put the O2 sensors where they were before on the stock headers. So yeah just need to get a tune.

Well looking at the picture you have the rear o2 near the cat and the other is near the stock locations... Not sure if you would just leave one unplug one sensor and just disable the code in the tune.

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