welding on a second Cat further down the exhaust
 

I have a Catless UEL headers not loving the sound tbh if I weld a second cat Hi-Flow down the middle of the exhaust would that not solve the sound issue without losing the benefit of having a Catless header ? im full stock besides over pipe and headers I can weld a cat where the catback meets the front pipe or is a second muffler a better choice.

Ask a muffler shop. Rally cars have a cat sitting at the end of the exhaust, having 2 cats is going to add a restriction and likely rob you of a little power. Just go back to stock headers.

I ran a Catless UEL with the rest of the exhaust stock and to me it wasn't loud at all, in fact it sounded stock most of the time - idle, and light throttle. You could hear the unequal rumble but quiet. Maybe it's me.

There's already a 2nd cat in the front pipe. I wouldn't add another cat, especially if you plan to weld it in. Like DarkPira7e said, you will add restriction, which will negate what you've done in getting a catless UEL.....

If you're looking to add cat back in, I would sell the Catless UEL and get a UEL with a high flow cat

A restriction is a restriction, it's better away from the header, but it's still a restriction. What are you trying to fix about the sound?

Try putting the stock overpipe back on.

A cat farther away from the engine will reduce noise but it will also be a less-effective cat.

i agree, this seems like an inefficient move for a desired outcome.

Use a resonator if you're just looking to reduce sound. That and a quieter muffler. Or add a turbo :D

A cat requires a certain temp to work, like near the engine. They are also expensive, and have to have contact with the exhaust gasses so the passages have to be small. (read restrictive). If sound is the issue see above, a resonator will probably help. Again nearer the engine is usually best as the pulses are more definded, but anywhere in the exhaust will help.

At low RPM especially from first to second when I'm setting off from the lights the sound can be extremely raspy give off an off based frequency, what bothers me is the lack of consistent sound build up like with a stock exhaust. I can deal with a bit of loud I just don't like the random flactuations I get out the back at low RPM. I don't want to spend money on a catback because my cars just a daily but I really want to keep the benifets of a catless header because the cars much more streetable with the extra torque and power.

for what you want to do, you're better off buying a 2017+ exhaust manifold and gutting the cat.

seems like you want the sound "benefits" of a stock setup without the flow restriction...

or you can go with a full setup like Apexi.

https://www.ft86club.com/forums/showthread.php?t=103338

Yeah I missed you were all stock - probably won't find an aftermarket catback that is quieter than stock anyways. Resonators would help.... but am I to understand you have a lot of rasp and have a stock exhaust including the stock 2nd cat in the FP? If so then I bet your raspy sound starting off is your overpipe rubbing on your chassis as the motor moves around. If so, you can just loosen it up a bit, yank on it and make some room.

Don't add a cat, consider using a dual resonated front pipe, resonators will help more that the cat, or go back to your stock front pipe which has a cat in it.

I agree with getting a dual resonated front pipe. I run a Fujitsubo.