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Old 08-15-2005, 10:45 AM
TurnAround TurnAround is offline
Location: Oregon
Join Date: Jan 2004
Posts: 358
Mein Auto: Z3C, Z3R, X5
I have a dumb question about removing the catalytic converter..

At some point in my Coupe's life I might do some kind of exhaust mod. To get more growel. I heard a 3.0i Coupe at DFest that obviously had some kind of mod.. but I didn't have a chance to talk to the guy. But I take from this.. that there must be some after market options for the 3.0i.

But here's the real question; I was considering the mod only for sound, as I have read that an aftermarket exhaust provides very little HP gain. But then it ocurred to me... our city has no air pollution auto check stations. No regulations at all, and no one to follow up on your car's setup. Portland does, but none of the other towns in OR have a DEQ station. We will likely NEVER get one either.

Soooo.... can I remove my catalytic converter? If I did that, as part of a custom exhaust mod, then wouldn't this provide quite a bit extra HP?

My guess at this is that I can't just do this because the engine's electronics will freak out.. looking for feedback from sensors mounted near the converter. Yes??

Also, would it effect the life of the engine at all? If this were a late 70's to early 80's car, I wouldn't hesitate.. as there are no electronics relying on the presence of the converter. But my impression is that modern cars have highly integrated pollution control systems that constantly feedback info to the engine for fuel and air ratio changes.

My other dumb question; Why do they call some aftermarket exhaust systems "Catback". Is this a play on words. Marketing language that suggests that, "hey, with our muffler, we'll give you some of the power back that your catalytic converter is stealing from you!", and it really has nothing directly to do with the converter? Or, do these systems actually replace the catalytic converter or modify it somehow?

Thanks guys.

'02 Z3 Coupe 3.0i [Hellröt II - Walnuß]
'03 X5 3.0i [GrauGrün - Beige]
'01 Z3 Roadster 3.0i [AlpenWeiß - TraumRöt]
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