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Headers and Emissions inspection?

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Old Jan 31, 2007 | 04:49 PM
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Default Headers and Emissions inspection?

When headers are installed do you still use catalytic converters? If not how do you Pass emissions inspections?
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Old Jan 31, 2007 | 05:12 PM
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moving the cats is against federal lwas. In short, you will not pass visual if the person doing the inspection knows what they are to look for.
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Old Jan 31, 2007 | 06:20 PM
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Originally Posted by ItalGermanVett
When headers are installed do you still use catalytic converters? If not how do you Pass emissions inspections?
it depends.

tuning would be the only possibly way to pass without cats.
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Old Jan 31, 2007 | 06:46 PM
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Originally Posted by knkali
moving the cats is against federal lwas. In short, you will not pass visual if the person doing the inspection knows what they are to look for.
IIRC the wording is more like Removing "PROPERLY OPERATING OEM" cats is against Federal law.

If they are not operrating properly they can be removed. Does not say you have to replace with OEM cats.

High flow cats work better and will still pass the OBDII, if the installer and tuner knows what they are doing.
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Old Jan 31, 2007 | 07:42 PM
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Originally Posted by AU N EGL
IIRC the wording is more like Removing "PROPERLY OPERATING OEM" cats is against Federal law.

If they are not operrating properly they can be removed. Does not say you have to replace with OEM cats.

High flow cats work better and will still pass the OBDII, if the installer and tuner knows what they are doing.

Actually, you can replace the CATS all day long (regardless if the originals have failed or not), you can't relocate them farther from the head (and they must be the same type, 2-way or 3-way - OEM or aftermarket). THe close proximity to the cylinder head heats them faster on cold starts so they can do their job properly. This is really only an issue at cold starts.
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Old Jan 31, 2007 | 08:01 PM
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yeah I said "moving" not replacing the cats in my post. Bottom Line: Got headers could have problems.
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Old Jan 31, 2007 | 08:09 PM
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Originally Posted by Beer Kahuna
Actually, you can replace the CATS all day long (regardless if the originals have failed or not), you can't relocate them farther from the head (and they must be the same type, 2-way or 3-way - OEM or aftermarket). THe close proximity to the cylinder head heats them faster on cold starts so they can do their job properly. This is really only an issue at cold starts.
BK my reading is that it is against the "law" again, to remove properly functioning cats. Even to replace them with properly designed cats.
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Old Feb 2, 2007 | 08:36 PM
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Originally Posted by AU N EGL
IIRC the wording is more like Removing "PROPERLY OPERATING OEM" cats is against Federal law.

If they are not operrating properly they can be removed. Does not say you have to replace with OEM cats.

High flow cats work better and will still pass the OBDII, if the installer and tuner knows what they are doing.
Actually my question should have been put this way. How do all these guys on CF install headers and stay legal. How do they install them and not relocate (or lose) the Cats? The headers that come stock are so short and pictures of the high performance headers that I have seen appear to be much longer. Who makes a street legal header?
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Old Feb 3, 2007 | 12:28 AM
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If you want street legal header, buy a set of shorty headers, Callaway offer them. But your not gonna see nearly the same gains you would get from long tubes.

IMO headers aren't the hardest thing to do on these cars. If you do fail an inspection, just swap on the stockers for the re-test.
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Old Feb 3, 2007 | 07:27 AM
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I run LTs with High flow cats. As long as the car has the Cats and passes the OBDII diagnotics, I would bet most places will pass the car.

Or I would also bet most corvette clubs have one or two guys who own an repair / emissions inspection station.

I have used three differnt places, and have had no problmes. and I dont even have mufflers any more, just staight pipes.

As some one mentioned it does take a bit to heat up the cats to get a proper reading.

All the headers are street leagal ( except for CA) and with High flow cats, I have Random Tech, and the headers have the O2 bung locations, should not be a problem.

Putting on shorty headers, with stock cats, and exhaust is a waist of time and money. Better to spend your hard earned money on a differnt exhuast system.
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Old Feb 3, 2007 | 07:38 AM
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Originally Posted by ItalGermanVett
When headers are installed do you still use catalytic converters? If not how do you Pass emissions inspections?
Call Nick over at American Racing Headers over in Amityville. He'll answer your questions. I just ordered a set from him. Awsome headers.
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Old Feb 3, 2007 | 07:42 AM
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Originally Posted by AU N EGL
I run LTs with High flow cats. As long as the car has the Cats and passes the OBDII diagnotics, I would bet most places will pass the car.

Or I would also bet most corvette clubs have one or two guys who own an repair / emissions inspection station.

Putting on shorty headers, with stock cats, and exhaust is a waist of time and money. Better to spend your hard earned money on a differnt exhuast system.
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