Opinions on the Ft86 Catted UEL headers

[Enrique_13]

Hey guys I’m new here, I just had a quick question. I purchased a used BRZ about 2 months ago, and I got a check engine light that read P0420 Catalyst System Efficiency below threshold (Bank 1). I was told this was the catalytic converter by the header going bad. So I was thinking of buying the FT86 Catted UEL header since it has the cat with it. Does anyone know if this would help ? Also does anyone know where I could find a video of this part on the BRZ with everything else stock on the car? Thank you guys 🙏

[coryandy]

I put a used FT86SF catted header on my car recently. It took about 3 days before the CEL came on. Luckily, I was on my way to get the car tuned when it happened.

I have heard some people have no problems, but some do. YMMV. I don't think the CEL will go away on its own either way. It will probably need reset regardless.

Edit: I do LOVE the difference it made in the torque dip, even before the tune!

[Enrique_13]

Thank you for the insight ���� How about the sound? Did you notice any better rumble ? After putting on the header?

[NoHaveMSG]

Just because you have a catted header does not mean it will not throw a CEL.

You can try to add an o2 sensor spacer but it is not guaranteed to work.

http://www.ft86speedfactory.com/o2-s...B#.WuZH6-jwbrc

Tune would be sure fix.

[chaoskaze]

if you wan a catted header that wont throw code ever...... Your choices is limited down to $$$$$

https://apexi-usa.com/exhaust/exhaus...-20-subaru-brz


I drove my car 30k miles before getting it tuned, tracked/auto corssed. no CEL ever.

[coryandy]

Originally Posted by Enrique_13

Thank you for the insight ���� How about the sound? Did you notice any better rumble ? After putting on the header?

It has a slightly more noticeable rumble, but not much. I already had the V1 catback as well, though.

[TofuJoe]

Why catted? The hp and torque gains are significantly less than catless. If you’re going catted to keep the sound down, a catless header and stock exhaust will give you more gains and still be pretty quiet. For reference, I ran the catted JDL with an OFT, custom tune, and briefly on the stock tune. A catted header without a tune is half assing what is already a compromise.

[Enrique_13]

Originally Posted by TofuJoe

Why catted? The hp and torque gains are significantly less than catless. If you’re going catted to keep the sound down, a catless header and stock exhaust will give you more gains and still be pretty quiet. For reference, I ran the catted JDL with an OFT, custom tune, and briefly on the stock tune. A catted header without a tune is half assing what is already a compromise.

Going catted because I wouldn’t pass emissions here in TX, at least that’s what I’ve been told. I was thinking of getting a Tomei Catless UEL header until I heard about emissions. I want a subie rumble , but I don’t want my car to sound obnoxious either you know ?

[TofuJoe]

Not sure how emissions laws work in TX. In CA, any modification to the exhaust will make you fail the visual. So putting the stock header back on would be needed whether you have a catted or catless header.

[extrashaky]

Originally Posted by Enrique_13

I purchased a used BRZ about 2 months ago, and I got a check engine light that read P0420 Catalyst System Efficiency below threshold (Bank 1). I was told this was the catalytic converter by the header going bad.

Maybe someone who is more familiar with our catalytic converters can clarify, but on some other vehicles you can get a catalyst inefficiency code from a failing O2 sensor that is reading the emissions incorrectly but isn't yet throwing a code for sensor failure. Personally I'd investigate further before shelling out the money for a new header.

(Unless you just WANT a new header, and you're using this as an excuse. In which case, grow some balls and just say you want a header.)

Originally Posted by Enrique_13

Going catted because I wouldn’t pass emissions here in TX, at least that’s what I’ve been told.

Correct. The "safety" inspection required in every county includes a visual inspection of the exhaust and emissions control equipment to make sure the exhaust is in good shape and you haven't removed the cats. You can replace cats with higher flowing cats, but you can't remove them altogether.

There's a separate emissions test required in 17 counties that includes OBDII testing. They hook up to your car to make sure you don't have any trouble codes stored and that your emissions readiness monitors show ready. For our cars, you're allowed one "Not ready" to still pass. Before you rely on a tune to correct a CEL for a catalytic converter, you might want to make sure it won't be detectable in the readiness monitors.