4-2-1 or 4-1
08-06-2001 | 06:00 PM
#11
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From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
QUOTE
Originally posted by Curtas:
I only have 1 cat (under the stereo, below the car), and I pass emissions. However, I do not know which (if you have Cali - 2 cats) cat is better, or if they are the same performance-wise.
I only have 1 cat (under the stereo, below the car), and I pass emissions. However, I do not know which (if you have Cali - 2 cats) cat is better, or if they are the same performance-wise.
Generally, the fewer cats...the better.
The Cali models are almost always down a few Hp and Torque due to the tougher emissions restrictions (ECU programming) and the extra cat.
08-06-2001 | 10:23 PM
#12
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I'm sorry, I wasn't clear. I meant, if you are in Cali and you wanted to keep one of the two cats, I don't know which one would be better to keep. One may flow better than the other, or they could both be exactly the same.
I don't want anyone thinking I support having two cats in the exhaust stream.
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I don't want anyone thinking I support having two cats in the exhaust stream.
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08-07-2001 | 05:03 AM
#13
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From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
Curtas:
To stay legal in Cali, you need to keep BOTH cats. You will not get your vehicle licensed with only one cat.
That being said...keep the rear cat.
The front cat is designed to work "hot" right off the engine. If you move it to a cooler location (farther back), it will not work properly.
You would be better served emissions and HP wise to remove both stock cats and go with a high flow performance cat.
To stay legal in Cali, you need to keep BOTH cats. You will not get your vehicle licensed with only one cat.
That being said...keep the rear cat.
The front cat is designed to work "hot" right off the engine. If you move it to a cooler location (farther back), it will not work properly.
You would be better served emissions and HP wise to remove both stock cats and go with a high flow performance cat.
08-07-2001 | 09:18 AM
#14
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QUOTE
Unless you bought your car in Cali, you only have 1 cat converter. Granted, you have 2 resonators, down there, but only the 1 cat up front. That means you will have to move/replace that front cat if you want to stay emissions legal.
Random, I bought my car in Fairfax, VA. The window sticker say Cali Emmisions $100, I have 2 cats. When I had my resonators removed I looked under the car while on the lift. QUOTE
The front cat is designed to work "hot" right off the engine. If you move it to a cooler location (farther back), it will not work properly.
You would be better served emissions and HP wise to remove both stock cats and go with a high flow performance cat.
You would be better served emissions and HP wise to remove both stock cats and go with a high flow performance cat.
This is helpful, I was just wondering could I get by with only 1 cat.
Evedently the Washington Dc area has a need for strict emmision laws also.
This is not a flame but I just want to clarify that even though I live on the east coast I do have 2 catalytic converters and am very aware ov how to identify them. I've posted about this before and was told I only had 1 cat. Thanks for any help you can provide and I respect your advice for you seem to be very resourceful and knowledgeable. smile.gif
08-07-2001 | 01:27 PM
#15
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im alos pondering a header. im ganna go with the 4-1. but from who??? is there a difference from Shark racing, HVE, HDK. is there any i forgot. any suggestions or experiences from any og these would be greatly appritiated. oh yeah, i have the KORE CAI(awsome by the way) and ganna go with the KORE exhaust. thanks
08-08-2001 | 01:27 AM
#18
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Tattooed, Get the 4-2-1 and move the cat and do leave at least the straight through resonator. I doesn't hurt the flow but if you take them both out the car will be LOUD and VERY raspy sounding. On the 98 we used to have we took both resonators of when we got the exhaust and ended up going back and putting a glasspack in to quiten it down some.
Even better let the get the header and cat done then start it and see how you like it. If it is not bad but not quite good enough then try taking out the first resonator and go from there.
Even better let the get the header and cat done then start it and see how you like it. If it is not bad but not quite good enough then try taking out the first resonator and go from there.
08-08-2001 | 11:00 PM
#19
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I have read recently about several people not in Cali having Cali emmissions. The easiest way to tell is on the window sticker, like you said.
Yeah, the DC area needs good emmissions laws, but they can be annoying sometimes. I don't have to go for 2 years now, so I'm doing exhuast and upgrade work now so if I do go out of spec, I can at least enjoy it for a while before the re-test.
Random, in Cali, is your downstream O2 sensor between the cats, or after the last one? Just curious.
a
[ August 09, 2001: Message edited by: Curtas ]
Yeah, the DC area needs good emmissions laws, but they can be annoying sometimes. I don't have to go for 2 years now, so I'm doing exhuast and upgrade work now so if I do go out of spec, I can at least enjoy it for a while before the re-test.
Random, in Cali, is your downstream O2 sensor between the cats, or after the last one? Just curious.
a
[ August 09, 2001: Message edited by: Curtas ]
08-09-2001 | 03:55 AM
#20
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From: Rancho Palos Verdes, CA
Vehicle: 2008 Toyota Prius 2006 Suzuki SV650S
QUOTE
Originally posted by Curtas:
Random, in Cali, is your downstream O2 sensor between the cats, or after the last one? Just curious.
Random, in Cali, is your downstream O2 sensor between the cats, or after the last one? Just curious.
Both are after the single cat (Due to turbo).
Normaly, the 2nd 02 sensor is downstream of the 2nd cat.