Question Headers, Sound, Emissions
 

Hey guys. Ive been reading this forum for Headers advice and instead of bumping an old topic I'll make my own for my questions.

My questions are about headers, cat/catless, sound and emissions.

1. I feel like my emissions concerns will end up with you guys replying with "just use your stock header" but will you most likely fail your emissions test by replacing your stock header with an aftermarket header w/ a cat? Will a tune with OFT do anything for the emissions test?

2. Going with an aftermarket header what is the obvious difference in sound between a cat and catless? Are they the same sound just a decibel difference? Does the catless have more rasp or again is it just a decibel difference?

3. I'm looking for more of a sound difference over stock rather than a power gain. UEL headers have the rumble that I desire but does a cat vs catless have a difference in rumble or again is it just a decibel difference?

4. So I enjoy the rumble of UEL headers and a bit of rasp at the higher RPMs. Does changing the catback exhaust do the most for changing the rasp sound and the sound overall? Would I be correct in saying that the UEL headers give you the rumble and a different catback exhaust for a rasp and louder sound or no?

1. the emissions is going to be based on what your state requires. i BELIEVE in my state (CA) they no longer do the sniffer test so not sure how the cat vs catless header can affect the test. the OFT won't doing anything regarding the emissions test but it will turn off a CEL so you can pass that part of the test.

2. the catless will have a slightly different tone than a catted but marginal at best. neither will give you much of a boost from stock as far as volume/rasp typically.

3. tone difference again. you will for sure smell the fumes if you go catless however.

4. UEL is generally going to give you the rumble (tone) but your other exhaust parts (front pipe - mid pipe - muffler ect) it going to go farther in determining rasp and volume.


these are all just my opinions and I am interested to see others opinions and if my ideas can be fine tuned/corrected

You should prob just do a N1 or N2 catback, that's what I have plus jrsc. Stock heads, stock over/front pipe. Its plenty loud PLENTY. and somewhat neighborhood friendly. Uel has rumble regardless of cat/no cat because it's the two different length heads that give it the sound, regardless of cat. Stock heads and N1 catback is plenty of aggressive rumble, and no worries about inspection.
To give some more perspective, my tune shop and many others say going from OEM eul to performance EL will actually make it quieter.
Uel for life \m/

If ur from CT take a look into dynotuning at EFI Logics, regardless of what exhaust path you take, they installed then dynotuned my jrsc. Legit shop.

1. Check with your state how they conduct emissions testing. Some sniff, some run OBDII for codes, some may physically inspect that the cats are there. For instance, VA has road-side sniffers that if you pass, you can pay your fee and be done with life, if you fail, you just have to go about it the normal way and get the OBDII read. I will not endorse which way to go about it, but the more educated you are re: your state, the more informed decision you can make.

2/3/4. Catless UEL headers are more UEL than the catted headers, because they don't have to account for meeting at the cat; therefore, you will get a bit more "subie rumble" from a catless UEL, but they are definitely louder and raspier by nature. You can control the sound volume/raspiness by changing your front pipe and catback to find a ton you enjoy. For instance JDL has a Ultra Quiet front pipe that is both catted and resonated. You can also get one just catted or just resonated. Some catback exhausts are just mufflers, some are also resonated. All comes down to how much noise you really want.

I personally ran the JDL Catted UEL, UQ Front Pipe, and Perrin 2.5" Resonated cat back, and got constant compliments on my sound. It wasn't "loud", almost silent at the highway cruising speeds, no low end drone, and solid amount of rumble. Now well...I'm still running all those pipes, but there have been some unforeseen changes from some extra power from my SC.

I love the sound the of the UEL, but i'd be lying if I said I didn't have a PTuning EL Race Header in my garage that will be going on at some point to squeak out some extra power, now that its my track toy.

So looking into this https://www.emissions.org/loc/connec...sions-testing/
It basically says I need "A" cat. But dont cars have more than 1 throughout the exhaust system? If theres 1 on the header and 1 on the mid pipe would you still pass if you removed 1 cat but still had 1 more? Seems like its just a visual test to see if you have one. It seems they only do a diagnostic check and not a real test unless the car is older than like 1996 and no smog test on cars newer than 2014.

Just buy one and try it.