catless header vs catless frontpipe

[steve99]

Originally Posted by kch

Thanks; I edited my response. Didn't know about the CEL with a catted header. Kinda defeats the purpose, doesn't it?

Edit: looks like a lot of the people getting CELs with a catted header were running the OFT OTS stage 2 tunes, which are designed for catless headers. Wonder if that was the problem...?

Could contribute, but may not be total cause.

ECU compares reading from the two 02 sensors pre/post cat and runs some weird algorithm/test/calculation to see if cat stock working efficiently. Since any aftermarket cat may result in different readings it possible it may cause the cel code. Any additional mods you do may also effect this.

If the guys have OFT or any other tuning device they could easily disable the P0420 code in their tune.

[akahenry]

You can do what I plan on doing. Catless Header with stock everything else (along with a tune--duh!) When time comes to get emissions testing, just swap everything back to stock exhaust parts, along with the tune, and enjoy your car.
Your best bet would be to get a front pipe with a high flow cat and a resonator to pretty much eliminate any type of rasp or unwanted attention. A catless front pipe vs a front pipe with a high flow cat will yield negligible gains, especially in NA Engines (generally speaking). In my honest opinion, if you're going to get a catted header--you're just wasting your money. Why get a catted header that will most likely than not cost more and reduce the amount of gains that you're able to maximize from swapping headers? If it's from a noise stand point, I can understand, but nonetheless I still think it's pretty redundant. Also considering that owners have reported getting CELs' thrown at them while running a catted header makes it even more unappeaing...

[steveholt]

Haven't owners of the ft86speedfactory uel catted header been having good fortune with no cel?

[Turdinator]

@steveholt what are you trying to achieve with a header? If it is power then you really should consider a tune first and then get a catless header. If it is more for sound then get a catted header and a mid pipe with a HF cat. That way you have your best chance at passing emissions.

[steveholt]

Originally Posted by Turdinator

@steveholt what are you trying to achieve with a header? If it is power then you really should consider a tune first and then get a catless header. If it is more for sound then get a catted header and a mid pipe with a HF cat. That way you have your best chance at passing emissions.

At the moment, it is more for sound than anything, performance gains would definitely be secondary to sound right now.

i really want that wrx sti boxer rumble...

i think i want to upgrade the header last because i want to diy everything, i have a shop that rents out tools and lifts at $15/hr and want to get to know my car from the back to front for the exhaust. I am a bit of a novice with cars but have custom built computers my whole life and also am a bit of an amateur freelance gunsmith. I am a tinkerer and I think I should be able to manage with my car, I feel most confident working from the rear of the exhaust to the front where the headers right now

i am currently only running a berk dual tip muffler delete but plan on changing to the following:
Invidia N1 catback -> berk high flow catted front pipe or invidia catless front pipe or invidia catless resonated front pipe -> stock overpipe -> stock header

based on the replies in this thread, i think the resonated catless front pipe would give me the best sound without the raspiness of a true straight pipe?

[Turdinator]

Originally Posted by steveholt

At the moment, it is more for sound than anything, performance gains would definitely be secondary to sound right now.

i really want that wrx sti boxer rumble...

i think i want to upgrade the header last because i want to diy everything, i have a shop that rents out tools and lifts at $15/hr and want to get to know my car from the back to front for the exhaust. I am a bit of a novice with cars but have custom built computers my whole life and also am a bit of an amateur freelance gunsmith. I am a tinkerer and I think I should be able to manage with my car, I feel most confident working from the rear of the exhaust to the front where the headers right now

i am currently only running a berk dual tip muffler delete but plan on changing to the following:
Invidia N1 catback -> berk high flow catted front pipe or invidia catless front pipe or invidia catless resonated front pipe -> stock overpipe -> stock header

based on the replies in this thread, i think the resonated catless front pipe would give me the best sound without the raspiness of a true straight pipe?

If you want the STi rumble stay away from EL headers, UEL will give you the sound you want. Also keep in mind adding a header makes the car seriously louder than stock so if your ultimate goal is to have a header choose a quieter cat back than you would normally choose..

If you are mechanically minded installing your own exhaust will be a piece of cake

[steveholt]

Originally Posted by Turdinator

If you want the STi rumble stay away from EL headers, UEL will give you the sound you want. Also keep in mind adding a header makes the car seriously louder than stock so if your ultimate goal is to have a header choose a quieter cat back than you would normally choose..

If you are mechanically minded installing your own exhaust will be a piece of cake

I get a little obsessive about everything having to be perfect with minimal compromise, i anticipate wnating to tear my hair out when the time comes to DIY all this.

i won't be getting a header for a long while, so i want the next best thing to it with the setup i typed up, thoughts?

[Turdinator]

Originally Posted by steveholt

I get a little obsessive about everything having to be perfect with minimal compromise, i anticipate wnating to tear my hair out when the time comes to DIY all this.

i won't be getting a header for a long while, so i want the next best thing to it with the setup i typed up, thoughts?

I haven't heard any invidia setups in person so I can't really comment. I personally would go a HF cat in the front pipe as you won't lose much by having it there but it means down the track you can have a catless header if you want.

[CoreVD]

Hello everyone, I renew this topic.
I would like to get your advice on which solution makes the most sense:
a) cattless manifold with front-pipe stock catted
b) catted manifold with front-pipe cattless


The smoke control do not care for me.
I'm interested more performance solution and less unpleasant odor (roadside checks...).I read that the best strength gains are obtained by removing the catalyst collector, ok.
I prefer A because the solution is not very expensive.

But I did this thought (perhaps stupid ):
The two series of catalysts (if I understand correctly) have 400 cells.
The solution a) would then 400 cells (Tomei 4-1 + stock front-pipe).
The solution b) would have 100 cells (HKS GT Spec + HKS duble resonated).

What do you recommend?

[Icecreamtruk]

Originally Posted by CoreVD

Hello everyone, I renew this topic.
I would like to get your advice on which solution makes the most sense:
a) cattless manifold with front-pipe stock catted
b) catted manifold with front-pipe cattless


The smoke control do not care for me.
I'm interested more performance solution and less unpleasant odor (roadside checks...).I read that the best strength gains are obtained by removing the catalyst collector, ok.
I prefer A because the solution is not very expensive.

But I did this thought (perhaps stupid ):
The two series of catalysts (if I understand correctly) have 400 cells.
The solution a) would then 400 cells (Tomei 4-1 + stock front-pipe).
The solution b) would have 100 cells (HKS GT Spec + HKS duble resonated).

What do you recommend?

Catless header and catted front-pipe with a hi-flow cat. Both stock header and stock front-pipe hurt the performance of the car greatly.

[aznatama]

Hi flow catted header and catless fp may be your best bet. Not much difference between hi flow and catless, and the hotter the gasses, the faster it'll flow through the cat. Also, no cel and no smell.

Sent from my D6503 using Tapatalk

[CoreVD]

Originally Posted by aznatama

Hi flow catted header and catless fp may be your best bet. Not much difference between hi flow and catless, and the hotter the gasses, the faster it'll flow through the cat. Also, no cel and no smell.

Sent from my D6503 using Tapatalk

Hello,
thanks for your answers.


unfortunately a friend that has the solution b) him came the CEL (header catted HKS GT Spec).
But I do not know if it was unpleasant odor. You're sure it does not?


With the solution b), which costs less than half of a), I could tune ekutec.
I would have more powerful and less odor.
My doubt is that I have never seen a chart with the solution b), I think the small diameter of stock front-pipe creates problems.

[Mr.Impreza]

Originally Posted by CoreVD

Hello everyone, I renew this topic.
I would like to get your advice on which solution makes the most sense:
a) cattless manifold with front-pipe stock catted
b) catted manifold with front-pipe cattless


The smoke control do not care for me.
I'm interested more performance solution and less unpleasant odor (roadside checks...).I read that the best strength gains are obtained by removing the catalyst collector, ok.
I prefer A because the solution is not very expensive.

But I did this thought (perhaps stupid ):
The two series of catalysts (if I understand correctly) have 400 cells.
The solution a) would then 400 cells (Tomei 4-1 + stock front-pipe).
The solution b) would have 100 cells (HKS GT Spec + HKS duble resonated).

What do you recommend?

dgsghh

[aznatama]

Catted headers cost under 1,000 new, and I just sold my p&l catted and ceramic coated header for about half that. They're not expensive. I had no cel either.

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