Question about headers/cats/no-cats.
Thread Starter
Race Director
Joined: Feb 2003
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From: Everyday you must choose between the pain of discipline and the pain of regret. Fredericktown, OH
Question about headers/cats/no-cats.
Ok, I know this has been discussed no less than 100 times, but help me solidify my understanding. On the LT-4 the O2 sensors are different and there are more than on an LT-1, correct?
If I go cat-less, do the O2 sensor dummies need to be installed in the exhaust tubing or can you just tie them up under the car out of the way?
When guys do long tubes on LT-4s do you run aftermarket cats (I do NOT live in an e-check area)? Do you leave cats off?
I am curious how this set up plays out in various scenarios as I am not a welder and don't want to get into welding O2 sensor bungs in new headers or elsewhere in an exhaust system.
Thoughts and comments are appreciated.
Thanks!
If I go cat-less, do the O2 sensor dummies need to be installed in the exhaust tubing or can you just tie them up under the car out of the way?
When guys do long tubes on LT-4s do you run aftermarket cats (I do NOT live in an e-check area)? Do you leave cats off?
I am curious how this set up plays out in various scenarios as I am not a welder and don't want to get into welding O2 sensor bungs in new headers or elsewhere in an exhaust system.
Thoughts and comments are appreciated.
Thanks!
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Originally Posted by LT-4 CE
Ok, I know this has been discussed no less than 100 times, but help me solidify my understanding. On the LT-4 the O2 sensors are different and there are more than on an LT-1, correct?
If I go cat-less, do the O2 sensor dummies need to be installed in the exhaust tubing or can you just tie them up under the car out of the way?
When guys do long tubes on LT-4s do you run aftermarket cats (I do NOT live in an e-check area)? Do you leave cats off?
I am curious how this set up plays out in various scenarios as I am not a welder and don't want to get into welding O2 sensor bungs in new headers or elsewhere in an exhaust system.
Thread Starter
Race Director
Joined: Feb 2003
Posts: 18,484
Likes: 1
From: Everyday you must choose between the pain of discipline and the pain of regret. Fredericktown, OH
So, if I go long tubes with cats, do you simply by a generic high flow cat from Random for example and then run the dummy O2 sensors?
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Originally Posted by LT-4 CE
So, if I go long tubes with cats, do you simply by a generic high flow cat from Random for example and then run the dummy O2 sensors?
Race Director
Joined: Aug 2003
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From: San Jose Pat Tillman - American Hero
Originally Posted by silver & red CE
If you're going to run cats AND you don't want to weld, by EM's cat set up. $595 isn't cheap. Another option is to buy some cartech cats (2 of 'em) and have a local shop weld it up.
Safety Car
Joined: Sep 2000
Posts: 3,524
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From: Hinckley Ohio
[QUOTE=Perfusion]Just keep in mind that the EM setup will be welded, yes, but it won't have O2 bungs - QUOTE]
I just went down in the basement to confirm that my new Exotic Muscle long tube headers in fact have O2 bungs on the collector tubes.
I am planning on Dynatech PowerCats 3.00" in/out to go with these headers. The rear O2 bungs are in the existing pipes after the cats. Going price for these cats are $149 each. Per some previous post on the forum these cats flow as good as any....can't confirm whether this is opinion or fact.
Plan to reuse all 4 oxygen sensors and keep system functional.
I just went down in the basement to confirm that my new Exotic Muscle long tube headers in fact have O2 bungs on the collector tubes.
I am planning on Dynatech PowerCats 3.00" in/out to go with these headers. The rear O2 bungs are in the existing pipes after the cats. Going price for these cats are $149 each. Per some previous post on the forum these cats flow as good as any....can't confirm whether this is opinion or fact.
Plan to reuse all 4 oxygen sensors and keep system functional.
Race Director
Joined: Aug 2003
Posts: 11,043
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From: San Jose Pat Tillman - American Hero
[QUOTE=LT4BUD]
Sorry! Didn't mean to imply that the headers didn't have O2 bungs in collectors - I was referring to the $549 Random Tech cat pipes that EM sells to go b/w the collectors and your catback. *Those* don't have bungs welded in 'em...the headers are straight, though...
Originally Posted by Perfusion
Just keep in mind that the EM setup will be welded, yes, but it won't have O2 bungs - QUOTE]
I just went down in the basement to confirm that my new Exotic Muscle long tube headers in fact have O2 bungs on the collector tubes.
I am planning on Dynatech PowerCats 3.00" in/out to go with these headers. The rear O2 bungs are in the existing pipes after the cats. Going price for these cats are $149 each. Per some previous post on the forum these cats flow as good as any....can't confirm whether this is opinion or fact.
Plan to reuse all 4 oxygen sensors and keep system functional.
I just went down in the basement to confirm that my new Exotic Muscle long tube headers in fact have O2 bungs on the collector tubes.
I am planning on Dynatech PowerCats 3.00" in/out to go with these headers. The rear O2 bungs are in the existing pipes after the cats. Going price for these cats are $149 each. Per some previous post on the forum these cats flow as good as any....can't confirm whether this is opinion or fact.
Plan to reuse all 4 oxygen sensors and keep system functional.
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Thread Starter
Race Director
Joined: Feb 2003
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From: Everyday you must choose between the pain of discipline and the pain of regret. Fredericktown, OH
[QUOTE=LT4BUD]
So you're saying the EM headers have bungs for all LT-4 02 sensors?!! That would be great. What source did you buy the headers from?
If you ran the headers and used your factory 02 sensors would you HAVE to run the cats?? Or could you go without and fab the exhaust to the collector? Sound is no issue and I am not in an e-check county. I can get the work fabbed at a very good friend's shop so it's no big deal.
Originally Posted by Perfusion
Just keep in mind that the EM setup will be welded, yes, but it won't have O2 bungs - QUOTE]
I just went down in the basement to confirm that my new Exotic Muscle long tube headers in fact have O2 bungs on the collector tubes.
I am planning on Dynatech PowerCats 3.00" in/out to go with these headers. The rear O2 bungs are in the existing pipes after the cats. Going price for these cats are $149 each. Per some previous post on the forum these cats flow as good as any....can't confirm whether this is opinion or fact.
Plan to reuse all 4 oxygen sensors and keep system functional.
I just went down in the basement to confirm that my new Exotic Muscle long tube headers in fact have O2 bungs on the collector tubes.
I am planning on Dynatech PowerCats 3.00" in/out to go with these headers. The rear O2 bungs are in the existing pipes after the cats. Going price for these cats are $149 each. Per some previous post on the forum these cats flow as good as any....can't confirm whether this is opinion or fact.
Plan to reuse all 4 oxygen sensors and keep system functional.
So you're saying the EM headers have bungs for all LT-4 02 sensors?!! That would be great. What source did you buy the headers from?
If you ran the headers and used your factory 02 sensors would you HAVE to run the cats?? Or could you go without and fab the exhaust to the collector? Sound is no issue and I am not in an e-check county. I can get the work fabbed at a very good friend's shop so it's no big deal.
Race Director
Joined: Aug 2003
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From: San Jose Pat Tillman - American Hero
Originally Posted by LT-4 CE
So you're saying the EM headers have bungs for all LT-4 02 sensors?!! That would be great. What source did you buy the headers from?
Safety Car
Joined: Sep 2000
Posts: 3,524
Likes: 4
From: Hinckley Ohio
Originally Posted by LT-4 CE
So you're saying the EM headers have bungs for all LT-4 02 sensors?!! .
I bought the EM headers from the forum GP....it is over
http://forums.corvetteforum.com/show...8&page=1&pp=20
Thread Starter
Race Director
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From: Everyday you must choose between the pain of discipline and the pain of regret. Fredericktown, OH
Thanks guys. For someone who built and raced carburated motors for years, this computer stuff is slowly coming.
So, one final shot at making sure I am clear.
The EM headers are set up for the front 02 sensors with bungs installed. The rear 02 sensors can be replaced with the sims and tied out of the way OR intalled after the cats (assuming I run cats).
So, one final shot at making sure I am clear.
The EM headers are set up for the front 02 sensors with bungs installed. The rear 02 sensors can be replaced with the sims and tied out of the way OR intalled after the cats (assuming I run cats).
Melting Slicks
Joined: Jan 2000
Posts: 3,418
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From: NW Chicago Suburbs
Originally Posted by LT-4 CE
...So, one final shot at making sure I am clear....
Le Mans Master
Joined: Feb 1999
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From: levittown pa. usa Even a bad day with my `Vette, is better than a good day at work
St. Jude Donor '10
Originally Posted by bogus
Why not make this simple and leave the cats on? If only for the air we breathe?
. I can`t believe how many people think they are going to get gobs of performance by ditching their cats. NEWS FLASH--- you don`t get that much more performance by ditching the cats ( except if they are plugged, in which case they should be replaced with new high flow ones ), & you do harm the air we breathe, by running without them. 
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Originally Posted by kenv
....you do harm the air we breathe, by running without them.
Safety Car
Joined: Sep 2000
Posts: 3,524
Likes: 4
From: Hinckley Ohio
Originally Posted by silver & red CE
everyone is chiming in on how to run cats and ditch the bogus rear O2s. i bet you jump all over smokers too...
Is it the possible lack of rear bungs??? I am planning on using the existing rear bungs when I install my headers with new high flow cats......is this going to work?????
Front ones if I understand correctly will be used to control A/F will cruising, thus giving max fuel economy, cleanest air, & cleanest spark plugs/cylinder heads, etc.
Burning Brakes
Joined: Sep 2004
Posts: 998
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I too am planning on long tubes, however, I am entertaining the idea of going cat-less. A buddy of mine had a 87 Formula 350 where he gutted the cat. Thing is, everytime you drove the car, you could smell the stench of gasoline. Do cat-less cars smell like this, or is this a product of a half-*** job of gutting the cats? Anyone without cats, please chime in...
P.S. Didn't mean to ***** out the thread, but oh well.
P.S. Didn't mean to ***** out the thread, but oh well.
Melting Slicks
Joined: Jan 2000
Posts: 3,418
Likes: 1
From: NW Chicago Suburbs
Originally Posted by LT4BUD
If the cats are in place then why not use the rear ones??? Don't need bogus rears or reprogramming
Is it the possible lack of rear bungs??? ...
Is it the possible lack of rear bungs??? ...
I too am planning on long tubes, however, I am entertaining the idea of going cat-less. A buddy of mine had a 87 Formula 350 where he gutted the cat. Thing is, everytime you drove the car, you could smell the stench of gasoline. Do cat-less cars smell like this, or is this a product of a half-*** job of gutting the cats? Anyone without cats, please chime in...
