how do i replace my cats completely
Thread Starter
Intermediate
Joined: Jul 2008
Posts: 26
Likes: 0
From: oswego il
how do i replace my cats completely
i want to lose the cats but i dont know what to do or how to do it, i have a 94 lt1 the cats are still on, all i want to know is how to get rid of them, i dont want them or need them.
Instructor
Joined: Mar 2005
Posts: 216
Likes: 3
www.ecklers.com they have all the pipes you need, or a muffler shop to put by-passes in there, but its against the law to remove them in most states, ecklers has a turbo pipe legal in 49 states, thats alot better then just by-passing them
Safety Car
Joined: Dec 2006
Posts: 4,290
Likes: 6
From: St Marys GA
Like dave said, it's illegal in most states. However, if you ask around you can normally find an exhaust shop who will do it. You may be able to buy all the pipes online to replace the cats with straight piping, but if it were me I'd probably just drop it off at the exhaust shop. Tell them to replace the cats with straight pipe, and be done with it.
Team Owner
Joined: Dec 1999
Posts: 34,873
Likes: 487
From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The LTx cats flow very well and should not take away a lot of HP or torque. A good cat back exhaust will provide power increases that are noticeable and a much better sound.
As far as removing the cats, you can do it yourself to save time and money, but it is a federal law that prohibits removable of the cats. In fact, most shops can be hit with a 5 figure fine if they get caught. Maybe find a small shop and ask. Don't forget to keep the O2 sensors in the original location.
Nothing wrong with keeping the air clean too..... More and more areas are going to required emissions inspections for cars. I'll bet that within 10 years, there will be mandatory emissions testing in every location in every location in every state.
As far as removing the cats, you can do it yourself to save time and money, but it is a federal law that prohibits removable of the cats. In fact, most shops can be hit with a 5 figure fine if they get caught. Maybe find a small shop and ask. Don't forget to keep the O2 sensors in the original location.
Nothing wrong with keeping the air clean too..... More and more areas are going to required emissions inspections for cars. I'll bet that within 10 years, there will be mandatory emissions testing in every location in every location in every state.
Instructor
Joined: Feb 2009
Posts: 191
Likes: 0
From: Woodstock IL
I deleted the cats on my car and it sounds much better without. Also, I picked up 1 tenth with long tube headers and the cat deleted. Check out the pick below.
Last edited by rogerdoger1993; Mar 22, 2011 at 12:22 PM. Reason: better explanation
Le Mans Master
Joined: Feb 1999
Posts: 6,470
Likes: 2
From: levittown pa. usa Even a bad day with my `Vette, is better than a good day at work
St. Jude Donor '10
The LTx cats flow very well and should not take away a lot of HP or torque. A good cat back exhaust will provide power increases that are noticeable and a much better sound.
As far as removing the cats, you can do it yourself to save time and money, but it is a federal law that prohibits removable of the cats. In fact, most shops can be hit with a 5 figure fine if they get caught. Maybe find a small shop and ask. Don't forget to keep the O2 sensors in the original location.
Nothing wrong with keeping the air clean too..... More and more areas are going to required emissions inspections for cars. I'll bet that within 10 years, there will be mandatory emissions testing in every location in every location in every state.
As far as removing the cats, you can do it yourself to save time and money, but it is a federal law that prohibits removable of the cats. In fact, most shops can be hit with a 5 figure fine if they get caught. Maybe find a small shop and ask. Don't forget to keep the O2 sensors in the original location.
Nothing wrong with keeping the air clean too..... More and more areas are going to required emissions inspections for cars. I'll bet that within 10 years, there will be mandatory emissions testing in every location in every location in every state.
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Race Director
Joined: Nov 2003
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Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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If I'm a state trying to balance a budget, spending extra money on emissions testing may fall to the bottom of the list. Especially with the issues I mentioned above. Who knows....
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
Simple, find a custom exhaust shop that respects dead presidents more than living ones. Don't expect a receipt, and if asked, they never saw you or heard of you. Nor you, them.
Your car will be ALOT louder. I mean ALOT.
You will also need to have your ecm tuned around them, or you will have a constant SES light, and your ecm will always be hunting for air/fuel trims to fix the "problem".
Also, should you want or need to sell it, this will hamper the sale tremendously.
You may want to consider long tube headers with high flow cats. It will give you better outcome in the long run.
Your car will be ALOT louder. I mean ALOT.
You will also need to have your ecm tuned around them, or you will have a constant SES light, and your ecm will always be hunting for air/fuel trims to fix the "problem".
Also, should you want or need to sell it, this will hamper the sale tremendously.
You may want to consider long tube headers with high flow cats. It will give you better outcome in the long run.
Instructor
Joined: Feb 2009
Posts: 191
Likes: 0
From: Woodstock IL
Simple, find a custom exhaust shop that respects dead presidents more than living ones. Don't expect a receipt, and if asked, they never saw you or heard of you. Nor you, them.
Your car will be ALOT louder. I mean ALOT.
You will also need to have your ecm tuned around them, or you will have a constant SES light, and your ecm will always be hunting for air/fuel trims to fix the "problem".
Also, should you want or need to sell it, this will hamper the sale tremendously.
You may want to consider long tube headers with high flow cats. It will give you better outcome in the long run.
Your car will be ALOT louder. I mean ALOT.
You will also need to have your ecm tuned around them, or you will have a constant SES light, and your ecm will always be hunting for air/fuel trims to fix the "problem".
Also, should you want or need to sell it, this will hamper the sale tremendously.
You may want to consider long tube headers with high flow cats. It will give you better outcome in the long run.
I ran my vette with long tubes and no cats and it did not change the sound at all really. As for the ecm. If you only delete the cats and run long tubes then you do not need to retune your ecm. Here is my video to prove it.
http://m.youtube.com/index?desktop_u...&v=EAVX0yVLlBo
Race Director
Joined: Nov 2003
Posts: 12,221
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
I also don't think Chris's car is that loud. Yeah, it's loud enough that after-midnite runs won't go undetected, but normal conversation is also possible. I especially like his result but I have to believe that Mag center resonator is partially responsible.
Le Mans Master
Joined: Jun 2006
Posts: 5,642
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From: One day you're a Comet...the next day you're dust... Arkansas
Le Mans Master
Joined: Dec 2006
Posts: 5,139
Likes: 482
From: H-Town Texas
When I read Chris's reply, I had to wonder if he was considering the difference between his 96 and the OP's model year. It's the difference between ODB1 and ODB2.
I also don't think Chris's car is that loud. Yeah, it's loud enough that after-midnite runs won't go undetected, but normal conversation is also possible. I especially like his result but I have to believe that Mag center resonator is partially responsible.
I also don't think Chris's car is that loud. Yeah, it's loud enough that after-midnite runs won't go undetected, but normal conversation is also possible. I especially like his result but I have to believe that Mag center resonator is partially responsible.
Also, even if the OBDI doesn't throw a code, I'm sure the computer is still hunting for fuel trims to correct the O2 reading it gets. That's whole purpose of the O2 sensor, to signal the ecm. I'm just saying that if he deletes the cat, he'll get a better result with a tune. Without doing this, he probably won't gain enough to make it worth all the trouble. Even with a tune, I don't think I saw enough to make it worth it. If the cats hadn't burned out, I still have them. But a $500 a side, se la vi.
Rogerdodger's gain came directly from the long tubes, with a tune I beleive he'd see even more gain.
Instructor
Joined: Feb 2009
Posts: 191
Likes: 0
From: Woodstock IL
I'm sure that the Magnaflow Resonator does quite a bit to tone it down. However, it is a ton louder than prior to the cats burning out. When I pull into the parking garage at work, I set off at least one car alarm every day
Also, even if the OBDI doesn't throw a code, I'm sure the computer is still hunting for fuel trims to correct the O2 reading it gets. That's whole purpose of the O2 sensor, to signal the ecm. I'm just saying that if he deletes the cat, he'll get a better result with a tune. Without doing this, he probably won't gain enough to make it worth all the trouble. Even with a tune, I don't think I saw enough to make it worth it. If the cats hadn't burned out, I still have them. But a $500 a side, se la vi.
Rogerdodger's gain came directly from the long tubes, with a tune I beleive he'd see even more gain.
Also, even if the OBDI doesn't throw a code, I'm sure the computer is still hunting for fuel trims to correct the O2 reading it gets. That's whole purpose of the O2 sensor, to signal the ecm. I'm just saying that if he deletes the cat, he'll get a better result with a tune. Without doing this, he probably won't gain enough to make it worth all the trouble. Even with a tune, I don't think I saw enough to make it worth it. If the cats hadn't burned out, I still have them. But a $500 a side, se la vi.
Rogerdodger's gain came directly from the long tubes, with a tune I beleive he'd see even more gain.
Race Director
Joined: Nov 2003
Posts: 12,221
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From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
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What happened to that Mustang-killer you talked about?
Seriously, if this is for the street, cats are a good idea. Less pollution and lower sound levels. Not that much difference in HP. I put some 200 cell/in cats on my 383 build. With today's pollution issues, most people won't be impressed that you ignore emissions issues. (Hence LT4Obsession's comment about resale.)
Race Director
Joined: Nov 2003
Posts: 12,221
Likes: 446
From: Overland Park Kansas
2020 Corvette of the Year Finalist (appearance mods)
C4 of Year Winner (appearance mods) 2019
Melting Slicks
Joined: Jun 2004
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From: Castro Valley CA