Frontpipe catless/hfc and emissions, sound level...
 

Hello everyone, after much use of the search function throughout the forums I was not able to gain a definitive knowledge for the following:

It is to my knowledge that running stock headers with the primary cat and deleting the secondary cat on the front pipe won't cause a CEL but what I was not able to get a definitive answer on is if it will cause emissions testing failures.
I am in illinois and according to the state website, they only do OBD tests here?
My car is a 2015, so i wont be tested for at least 4 years i think at the minimum, then every 2 years after that i believe.

My current setup is all stock except for a berk dual tip muffler delete axleback...

I am interested in either a high flow catted front pipe or a catless front pipe.

I imagine I will have some gains or responsiveness with a front pipe upgrade but in either case of the high flow catted or catless front pipe, i imagine it is going to be substantially louder paired with my berk dual tip muffler delete?

I am not entirely sure what my plans for my car is at this point, i am leaning towards FI. I just want to make the affordable upgrades to begin with, the berk dual tip muffler delete was reasonable in price and i think the next in line for affordable would be either the berk high flow catted front pipe or berk catless front pipe.

My ultimate goal is to get a UEL catted header from ft86speedfactory, or a UEL catted header that wont throw a CEL and can still pass emissions reasonably consistently.

If I were to replace my uel catted header i'd probably get a new axleback with muffler or a catback system and sell the berk dual tip muffler delete...

the berk dual tip muffler delete is pretty loud and droney, but i can tolerate it, im wondering how much louder it might be with the above considerations...? keeping the midpipe stock will probably tame the sound a bit too? considering it is narrower in diameter than catback system midpipes and also has a stock resonator on it?

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Dunno about noise but you should probably know that the cats on the headers are not the primary cats.

Wrong. The cat in the header is the primary. Thats why the catalytic efficiency sensor is in the header and not the front pipe. I've been under the car, and have seen it.

The car will be substantially louder with a catless front pipe, and a bit louder with a high flow cat.

If I were you, I would get the catted front pipe. That way once you get the header, you still have a greater chance at passing a sniffer test than with the catless pipe. Kind of a "two is better than one" mentality.

my current set up with just the berk dual muffler delete is pretty loud as it is and droney but primarily on the low end. i want a little something extra in the mid range.

2 cats is much more likely to pass an emissions than 1 even if the 1 is the primary? what exaactly i a sniffer test btw? is that where they attach a pipe to the tailpipe?

i won't be getting the header for a long long time, that's why i want to do what i can with the front pipe for now. since it'll be only a $200 or so mod, if i go with the berk front pipe.

so it's 100% that a catless frontpipe wont throw a CEL as long as the stock header+cat is there? what is your opinion on passing emissions with a stock header/cat + catless front?

p.s - how much louder are we talking here, by substantial like unbearable? comparing catless to hfc

If more midrange is what you want, you won't get it with a front pipe. You'd be better off just getting an OpenFlash Tablet and a uel header.

Yes. And a sniffer test is where they hook up a sensor or machine to your tailpipe to see/make sure your car isn't putting out too much carbon monoxide and other bad stuff.

A catless front pipe will not ever throw a P0420 catalytic efficiency below threshold CEL code.

Cats do a fair amount to muffle sound, but "too much" is very relative. What's way too loud for me might be perfect for you. But the catless pipe will be louder.

Would it create more rasp? i just don't want to risk my car sounding ricey or muscly...

my ultimate goal is to get that infamous subaru boxer rumble or something close to it without a uel header for the time being since it will take some time to afford a header

in terms of gains, i'd imagine a straight catless front pipe would be better than hfc?

A catless front pipe will make your exhaust sound a lot more raspy.

You won't get any sort of boxer rumble without an UEL header. Thats that. This car has an equal length header.

High flow cats are not nearly as restrictive as most people think. You'll get 1-2 more horsepower, TOPS out of a catless pipe. Its not worth the rasp.

You're better off getting a catless header and tuning the car, otherwise you're just wasting your time getting these mods unless you enjoy expensive changes in sound. Besides, catted headers aren't guaranteed to NOT throw a CEL.

Know what I do for inspection? Easy steps:

1. Flash your car back to stock tune (Most tuners provide this) and feel how sluggish and weak sounding your car is.
2. Drive to inspection place and bring your laptop with you.
3. Yay I passed inspection!
4. Flash it back in the parking lot after inspection.
5. Bask in glory of your victory of breaking the law but no one knows that. Enjoy the sound/gains you once had.

The tune is so crucial to this car, and make sure it is a good tune.

Woah, woah, woah, you're saying I'd have to flash my car back to stock to pass emissions, even if I have both cats still?! :mad0260:

Man i dunno how you guys run with catless header. I am running Perrin 2.5 res CBE and the Perrin catted front pipe. I am pretty much going deaf because of it.

gotta keep the crickets at bay somehow :D

I have the same setup with a Tomei EL header and I don't find it too loud at all once you get past the cold start warm up cycle. It's quiet when cruising, but loud when you get on it, but not overly loud. My WRX with full TBE was much louder.

Well there is no drone but it is pretty loud. But then again i am usually cruising at around 3k in 6th.