gutting down pipe cat?

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gutting down pipe cat?

Postby rallyfan » Sat Oct 16, 2004 3:19 am

does anyone know if there are any benefits to gutting out a down pipe cat, and if so, will it cause any damage to engine or turbo? thanks
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Postby zblu81 » Sat Oct 16, 2004 3:23 am

lots of people do this as a 'free' mod. It doesn't hurt anything, just frees up the exhaust flow.
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Postby shoteh » Sat Oct 16, 2004 4:06 am

might be a little loud on the ears and not pass emissions for some of you guys...
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Postby Stubble » Sun Oct 17, 2004 12:14 am

I found the volume went up a small amount, but now I can hear the turbo whistle when it spools. Kinda neat. A few guys on this board report passing smog with gutted primary cat and stock mid-pipe cat. Smog's not a problem hear in Manitoba though!

BTW, mine was nearly plugged after 190,000 km. Car wouldn't boost much past 1-2 psi. Gutting it restored significant boost. I am no longer being beaten by girly 1.6L Civics.
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Postby BraveUlysses » Sun Oct 17, 2004 4:57 am

The precat in the downpipe only helps with cold-start emissions, so taking it out is unlikely to affect your emissions status.

Don't breathe any of the material that floats out. Use a dustmask and try to do it outdoors and inside a few garbage bags too.
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Postby T-spoon » Sun Oct 17, 2004 5:50 pm

The car eggbeater has now passed Harris County (Houston) emissions easily (better than many newer cars I've seen) with the aussie DP and stock mid-cat, so gutting primary as has been said is unlikely to effect testing. It is highly illegal to tamper with a cat though. If you do it, do it at your own legal risk and make sure you don't include anyone in the activity that doesn't know the risks etc. Don't throw the material away in your parents or friends trashcan or at work etc. The EPA would have a field day, even though the risks of discovery are pretty small, be aware of what COULD happen.
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