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Cats or no cats?

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Old Oct 29, 2007 | 05:41 PM
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Default Cats or no cats?
I live in an area in Colorado where there is no emission testing. This means I have the option of not running cats on my car when I put headers on.

For those who've BTDT, what are the pros and cons to running with or without cats? Considerations? Noise, power gains vs. cats? Will I need "dummy" O2 sensors?

Any help would be appreciated!

TIA!
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Old Oct 29, 2007 | 06:38 PM
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Depends... You really don't gain that much HP but it does smell sometimes! You have have your CEL Tuned out so no need for 02 Sims.
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Old Oct 29, 2007 | 06:51 PM
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I have heard of a very odd smell coming from running without cats. I also have heard there is more resonance inside the cabin. The cats only lose you about 4-6 rwhp, hardly noticable, especially at higher altitudes.
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Old Oct 29, 2007 | 06:54 PM
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No real gain and the possibility of prosecution; federal felony. Not worth it.
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Old Oct 29, 2007 | 06:56 PM
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Originally Posted by Evilways
I have heard of a very odd smell coming from running without cats. I also have heard there is more resonance inside the cabin. The cats only lose you about 4-6 rwhp, hardly noticable, especially at higher altitudes.
Thanks, Evilways, and nutz- exactly the info I was looking for. I've run cars w/o cats before (AC Cobra replica), and had no odor. If it's only 4-6rwhp, I'll go ahead with the cats, and keep the "enviro" in me at peace.

I'm almost suffering from information overload after reading all the exhaust options/opinions here. Great to have access to all this, but man, so much info!

Much appreciated.
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Old Oct 29, 2007 | 07:06 PM
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Originally Posted by scottycards
Thanks, Evilways, and nutz- exactly the info I was looking for. I've run cars w/o cats before (AC Cobra replica), and had no odor. If it's only 4-6rwhp, I'll go ahead with the cats, and keep the "enviro" in me at peace.

I'm almost suffering from information overload after reading all the exhaust options/opinions here. Great to have access to all this, but man, so much info!

Much appreciated.
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Old Oct 29, 2007 | 07:22 PM
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You don't smell anything because you are either used to it or you are smelling gas that have no taste to it. (NO). Save some brain cells, leave a cat on. There is nothing worse than smelling a polluter, kind of like smelling a person with really bad BO
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Old Oct 29, 2007 | 11:00 PM
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I'm running no cats and may convert back to high flow cats. Love the sound, hate the odor.
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Old Oct 29, 2007 | 11:53 PM
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Originally Posted by Evilways
I have heard of a very odd smell coming from running without cats. I also have heard there is more resonance inside the cabin. The cats only lose you about 4-6 rwhp, hardly noticable, especially at higher altitudes.
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Old Oct 29, 2007 | 11:59 PM
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stinky
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