99Slammed

Petza914

You'll likely never pass CA emissions with a catless setup and may fail the visual inspection with anything not stock, as shiny stainless pipes are a dead giveaway. Your best bet may be a gundo hack or Fisters since the mufflers still look stock to the untrained eye. Unless you get a custom tune, doing anything other than 200 cell hi-flow cats will also throw CEL codes too.

GT3_ISH

You'll have to go catted and a gundo or fisters in youre in a state with inspections.

Most X-pipes as Petra stated are a dead giveaway, I have seen a few catted crossover pipes that may pass however, might be worth looking into.

99Slammed

Sneaky Pete

If you have the time you should contact Darin Fister at his shop. He usually answers the phone. I have his cans with 200 cell cats and love the sound.

Soul Performance

We have a lot of information and sound clips on 200 cell catalyst pipes and our valved exhaust in our 997.1 Carrera development thread. As you are in CA, a valved exhaust might give you the sound you are looking for without attracting too much attention from the CARB monster.

platinum997

Wondering the same. See alot of info on catted setups. .1 xpipe cats or .2 headers with cats but how the sound with no cat or the race headers on .2.

Worth it in terms of performance vs catted?

No carb for alot of us.

user 72902

platinum997

Yes.. you can code it out, use mini cats or electronic O2 simulators.

BF951

i have a Gundo hack to my stock mufflers and the FabSpeed 200 Cell cats and X-Pipe. Sound is not over the top but is very much woken up. I like it very much!
I won't be going back to stock so long as I own the car.

Good luck with your decision.

user 72902

Didn't know about these. My Porsche turbos were OBDI and benefited greatly sans cat. If I go back to turbos I'll keep this info in mind. Currently running headers, 200 cell cat, and after market mufflers that sound nice to me. Even with my dyno tune I'd doubt I'd see any benefit by removing the cat on a NA car. Thanks!

platinum997

Agree, minimal at best. On a previous FI car, I picked up 20whp removing them though.

rootwyrm

Modern engines are designed to run with catalytic converters. Not without. The perceived 'loss' is already engineered for. Which is why removing cats on anything but turbos has more cons than pros by a county mile, but replacing with high flow properly functioning ones can add power. (It adds power on turbo because of flow, while making fuel mix harder to manage. Meaning: high flow cats > no cats, again.) Not only that, but it is never legal to remove a catalytic converter for any reason. It's literally a criminal act for any shop to remove cats and has been since 1977.

platinum997

Also a crimal act to go above the speed limit created in 1861. I guess we all have our boundaries and what were willing to bend.

99Slammed

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