Title says it all. I want to swap out my downpipes for better performance and sound. I'm running a stage 1 M Engineering tune already.

Looking to hear anyone's experience with either. Specifically in performance and sound.

Brownie points if you also have a recommendation for an O2 socket you know works.

Read through the various exhaust threads. Catless, 100, and 200 are very common combinations.

https://a.co/d/2dtevFJ

I skimmed through a bunch and most of the conversations just got detailed with no one answering with their actual experience.

To simiplfy it, power differences between the most common three are marginal. Catless you will deal with the smell and it will be louder than 100 or 200 CPSI cats. You will definitely get a CEL with a catless setup.

I guess my question is how significant is the sound difference between catless and 100? Not worried about the CEL because I can just get the tune to clear it.

I had an M3 before this car and was catless. Didn't mind the smell but some seem to think in a targa it's a stark difference. So wondering about that too

There really isn’t! If you don’t mind the smell, just go catless.

Thanks. Any recommendations on which one? I've seen the Soul and Fabspeed ones promoted a lot. New to Porsche modding so unsure what companies are preferred or better

Now THAT’s where you’ll have to do some reading because results vary and people have lots of extensive feedback about all of them. Some have Soul, others Europipe or Fabspeed. I have BRE cats, and I went that route because of inconsistencies, my aversion to CEL’s (…even though I have a tune), and metal choice. Catless wasn’t a consideration for me at all because I didn’t want to deal with the smell and despite being in law enforcement, I didn’t want to get that one guy who state refs me. Being between CA and NV on any given day - and with NV becoming even more strict than CA - it just wasn’t worth it.

Great this is helpful thanks

I’ve got the Kline 200 cel cats and valves cat back, both in Inconel, with a stage 2 m-engineering tune. I find it perfect for my use on my slick top 24 T. I found the @Flat6Motorsports exhaust reviews on YouTube and their website really helpful, though not all inclusive of every brand and of course subject to all the problems with recorded sound. If you have a local PCA, I’d try to listen in person to some, hearing them of course makes a large difference. I was able to hear a catless setup before I did mine and and for my use, it was way too loud. I also own a decatted 2016 M5 and an LT swapped Jeep, both of those stink to high heaven. I’d also note that the aerodynamics in the jeep make it impossible not to smell it while driving. I suspect the targa aero is a bit better than my refrigerator on wheels, but something to think about if you go catless. Also note that even my OEM + Kline setup has a decent amount of drone at 2-2.5K, I’m thankful I stayed valved.

Thanks this is all great info. Especially hitting up a local PCA

I went with this setup and it's absolutely amazing in my opinion. No CELs at all. For you since you've already paid for the M-Tuner package, after you get the Cats and or Exhaust, they can provide a new tune file to you.

Note: Below is for my 2024 Porsche 911 Carrera T (992.1)

Soul Valved Performance Exhaust = https://soulpp.com/product/porsche-9...xhaust-system/
Soul Performance Cats = https://soulpp.com/product/porsche-9...ic-converters/
M-Engineering Stage 2 Tune = https://www.m-engineering.us/product...he-992-carrera

You can hear my video =

I personally would always go catted over catless, I don't like dealing with the smell anymore. + power difference is slim. If its a weekend car, want max power and you don't mind, then catless spools are the best.

We do a lot of Soul Performance catted and catless though so we can get you taken care of there! (Catless brand doesn't really matter, its just an open pipe, just want good fitment)

-Josh

I’ve moved away from running catless setups in most cases, unless it's a dedicated race car.

Catalyst technology has advanced significantly in the past few years, so the power difference is not what it once was.

Plus, you won't have the raw gas smell and emissions issues (in most areas) - I also think catted set ups have a 'cleaner' sound to them.

Happy to help with either