Headers...are all considered illegal
Thread Starter
Burning Brakes
Joined: Jul 2005
Posts: 750
Likes: 0
From: Nutley New Jersey
Headers...are all considered illegal
OK...stupid question
Are all headers considered "illegal", and thus the car will not pass a typical state inspection or is the issue more with the CATS?
What are the options to remove the stock manifolds...to upgrade performance, all while keeping the car street legal for state inspection?
Are all headers considered "illegal", and thus the car will not pass a typical state inspection or is the issue more with the CATS?
What are the options to remove the stock manifolds...to upgrade performance, all while keeping the car street legal for state inspection?
Moderator
Joined: Dec 2002
Posts: 40,901
Likes: 4,352
From: Lakewood Ranch, FL
No long tube headers are EPA legal for the C6. It violates EPA regulations to move the Cats from the OEM location or to replace the OEM cats with other than OEM unless the OEM is defective. Used to be, all that it took to pass smog test was to get the right numbers on the sniffer. Now (in most places anyway - including NOVA) smog testing is done via the OBDCII connection, a Gas Cap pressure test and - importantly - a visual. If the tech is up to his task, you WILL fail with headers.
Reportedly, Callaway was trying to get shorty headers that used the OEM cats in OEM location CARB approved but from what I hear, they discontinued from lack of sales interest.
Reportedly, Callaway was trying to get shorty headers that used the OEM cats in OEM location CARB approved but from what I hear, they discontinued from lack of sales interest.
Instructor
Joined: Nov 2007
Posts: 192
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From: Alabama
St. Jude Donor '08
Safety Car
Joined: Sep 2006
Posts: 3,922
Likes: 4
From: Cheektowaga NY
St. Jude Donor '08
Burning Brakes
Joined: Sep 2007
Posts: 1,046
Likes: 31
From: Cary IL
I know its not apples vs. apples but the car I sold to get this Vette was a 2003 Mustang Cobra and it had the OBD2 connection.
I had that bastard so modified it was hilarious. Kenne Bell 2.8L High Output Twin Screw Supercharger, 60# Injectors, Bassani X-Pipe with NO cats, Magnaflow Exhaust, and a tune from Bob Kurgan that put almost 600HP to the back tires.
I passed the EPA test in Crystal Lake, IL with flying colors.
Laughed my *** off.
Probably will look at something different with a 08 Vette I am not sure. I just know all he did was plug the connection under the dash for a few minutes and I was good to go. No lifting of the hood or mirrors under the car for me.
Good luck in your state though they are all probably a little different on how strict they are.
I had that bastard so modified it was hilarious. Kenne Bell 2.8L High Output Twin Screw Supercharger, 60# Injectors, Bassani X-Pipe with NO cats, Magnaflow Exhaust, and a tune from Bob Kurgan that put almost 600HP to the back tires.
I passed the EPA test in Crystal Lake, IL with flying colors.
Laughed my *** off.
Probably will look at something different with a 08 Vette I am not sure. I just know all he did was plug the connection under the dash for a few minutes and I was good to go. No lifting of the hood or mirrors under the car for me.
Good luck in your state though they are all probably a little different on how strict they are.
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Safety Car
Joined: Nov 2007
Posts: 4,537
Likes: 1,404
From: Bethesda MD
Over the Christmas holiday I installed a 2007 C6 Z06 exhaust system (manifolds, Cats, H pipe) plus Corsa Z06 3 inch Sports on my 2006 C6 A6. I did a pre and post dyno run on a Dynojet 248 for comparasion. The car was tuned (A/R ratio, timing, etc) to the same level for each dyno pull. Pre Z06 exhasut was 343 rwhp and post was 373 rwhp. There are a bunch of Z06 guys putting headers on the Vettes. The shop I use had 4 pairs just collecting dust. However, the Z06 guys tend to keep their NPP mufflers, but Corsa, B&B and Borla all make 3 inch Z06 mufflers. The installation was not difficult. I bought GM LS7 manifold gaskets and some O2 sensor wire extensions for the forward O2 sensors. The clearance around the A6 transmission is tighter than I want, so I will get some minor exhaust pipe work. Manual transmission C6's should be no problem at all. Bottom line. I think this is a good 30 hp mod for C6 Vettes if you can get your hands on a discarded Z06 exhaust system.
Tech Contributor
Joined: Jul 2002
Posts: 14,950
Likes: 266
From: St. Louis, MO
St. Jude Donor '08
I noticed in the Corvette Factory show on Discovery the other day, the LS7 builder made a special point to state how complex and expensive those welded Z06 manifolds are.
Moderator
Joined: Dec 2002
Posts: 40,901
Likes: 4,352
From: Lakewood Ranch, FL
That is very good information, thanks for the heads up. I only had 386/378 with headers and ported intake through 3.90 gears in a MZ6, so those figures in an automatic are as you noted right on par with headers.
I noticed in the Corvette Factory show on Discovery the other day, the LS7 builder made a special point to state how complex and expensive those welded Z06 manifolds are.
I noticed in the Corvette Factory show on Discovery the other day, the LS7 builder made a special point to state how complex and expensive those welded Z06 manifolds are.
Team Owner
Joined: Oct 2004
Posts: 27,420
Likes: 64
From: San Clemente CA
No long tube headers are EPA legal for the C6. It violates EPA regulations to move the Cats from the OEM location or to replace the OEM cats with other than OEM unless the OEM is defective. Used to be, all that it took to pass smog test was to get the right numbers on the sniffer. Now (in most places anyway - including NOVA) smog testing is done via the OBDCII connection, a Gas Cap pressure test and - importantly - a visual. If the tech is up to his task, you WILL fail with headers.
Reportedly, Callaway was trying to get shorty headers that used the OEM cats in OEM location CARB approved but from what I hear, they discontinued from lack of sales interest.
Reportedly, Callaway was trying to get shorty headers that used the OEM cats in OEM location CARB approved but from what I hear, they discontinued from lack of sales interest.
Team Owner
Joined: Feb 2000
Posts: 45,600
Likes: 892
From: Texas
CI 1-4-5-8-9-10 Vet
St. Jude Donor '03 thru '10, '17
This was posted recently on LS1Tech:
Wow !! That's an interesting concept! 30 HP and it would pass a visual inspection. No way would a smog tech know the difference. This could be promising.
Over the Christmas holiday I installed a 2007 C6 Z06 exhaust system (manifolds, Cats, H pipe) plus Corsa Z06 3 inch Sports on my 2006 C6 A6. I did a pre and post dyno run on a Dynojet 248 for comparasion. The car was tuned (A/R ratio, timing, etc) to the same level for each dyno pull. Pre Z06 exhasut was 343 rwhp and post was 373 rwhp. There are a bunch of Z06 guys putting headers on the Vettes. ..................Bottom line. I think this is a good 30 hp mod for C6 Vettes if you can get your hands on a discarded Z06 exhaust system.
Wow !! That's an interesting concept! 30 HP and it would pass a visual inspection. No way would a smog tech know the difference. This could be promising.
Safety Car
Joined: Jul 2000
Posts: 3,596
Likes: 37
From: Orange County CA
Maybe I was just lucky...but I had LT headers on my old C5 for 5+ years and it passed inspection every time. I was nervious the first time...but there were no issues.
Charley
Team Owner
Joined: Oct 2004
Posts: 27,420
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From: San Clemente CA
This is the sticker for the K&N air charger on my C6.
Team Owner
Joined: Sep 2003
Posts: 43,084
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From: Raleigh / Rolesville NC
Is the key word here 'defective'?? Would a screw driver accidentally though a Cat cause it to be defective? Therefore . . . .
Moderator
Joined: Dec 2002
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From: Lakewood Ranch, FL