How big of a part does the cat-back play in emissions?
07-26-2006, 11:18 PM
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How big of a part does the cat-back play in emissions? I am looking into changing up my cat-back system in the next few weeks and was wondering if muffler/piping selection and style makes that big of a difference in emissions testing results. Keep in mind my car is OBDI and must pass sniffer. Also, would adding a 2nd cat help a lot in getting my car to pass? Thanks.
07-26-2006, 11:31 PM
#2
You would have to add another cat close enough to the motor so it can actually work other wise it will be like adding a really restrictive muffler with no benefits.
Cat back wont determine if you pass wor fail. You have to have one that is 50 State Legal if you are worried about that. Is your other catalyst not in working condition or something?
Cat back wont determine if you pass wor fail. You have to have one that is 50 State Legal if you are worried about that. Is your other catalyst not in working condition or something?
07-26-2006, 11:36 PM
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Originally Posted by orangeapeel
You would have to add another cat close enough to the motor so it can actually work other wise it will be like adding a really restrictive muffler with no benefits.
Cat back wont determine if you pass wor fail. You have to have one that is 50 State Legal if you are worried about that. Is your other catalyst not in working condition or something?
Cat back wont determine if you pass wor fail. You have to have one that is 50 State Legal if you are worried about that. Is your other catalyst not in working condition or something?
07-27-2006, 07:12 AM
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None directly, however if it causes the a/f ratio to alter then it may affect emissions.
As for the extra cat, well I don't know. You probably need a chemist to answer this. The question is "does running multple cats have accumulative effect?"
It's like boiling water, under standard atmospheric pressure water will boil at 100 degree's C, not matter how more you try and heat it up, it will never exceed 100 degree's C.
So if the exhaust gas as already passed thru a CAT where a chemical reaction has taken place, will there still be a reaction if it's then passes thru another cat? Or will there be no further reaction?
As for the extra cat, well I don't know. You probably need a chemist to answer this. The question is "does running multple cats have accumulative effect?"
It's like boiling water, under standard atmospheric pressure water will boil at 100 degree's C, not matter how more you try and heat it up, it will never exceed 100 degree's C.
So if the exhaust gas as already passed thru a CAT where a chemical reaction has taken place, will there still be a reaction if it's then passes thru another cat? Or will there be no further reaction?
07-27-2006, 08:20 AM
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Well, the Cat itself is just that, a catalyst. Chemistry classes teach that a catalyst just helps to speed up a chemical reaction, not actually be part of the input or output compounds. That's why platinum is used, it's a well known catalyst.
A catalyst helps to break and reform the molecular bonds of the compounds used, in the case of automobiles to help them change to less harmful compounds before exiting the exhaust. The truth is that the conversion taking place in the catalytic converters will still happen to the gasses even if they're released directly to the atmosphere (i.e. no cats), but at a much slower rate than takes place in the converters. The other caveat to that is that the catalytic converters on cars have to be very hot to start working the breakdown of the compounds (extra energy is required to break the bonds in an endothermic reaction) and that's why the federal and California regulations require that the catlytic converters not be moved any further from the heads than they are when the car leaves the factory. The further from the heads, the longer it takes them to heat up and start working.
A catalyst helps to break and reform the molecular bonds of the compounds used, in the case of automobiles to help them change to less harmful compounds before exiting the exhaust. The truth is that the conversion taking place in the catalytic converters will still happen to the gasses even if they're released directly to the atmosphere (i.e. no cats), but at a much slower rate than takes place in the converters. The other caveat to that is that the catalytic converters on cars have to be very hot to start working the breakdown of the compounds (extra energy is required to break the bonds in an endothermic reaction) and that's why the federal and California regulations require that the catlytic converters not be moved any further from the heads than they are when the car leaves the factory. The further from the heads, the longer it takes them to heat up and start working.
