Removing the cats?
Thread Starter
Pole Position
Joined: Oct 2004
Posts: 3,397
Likes: 14
From: Maryland
Removing the cats?
My car wont pass MD emissions because of my check engine light being on with the TC.
So, I'm figuring if I'm not gonna pass ANYway, why not go ahead and just remove the catalytic converters?
I have the Tanabe MT Exhaust, and the SRT intake. What are the pros and cons of having no cats? Is there any performance gain at all? Should I even bother?
So, I'm figuring if I'm not gonna pass ANYway, why not go ahead and just remove the catalytic converters?
I have the Tanabe MT Exhaust, and the SRT intake. What are the pros and cons of having no cats? Is there any performance gain at all? Should I even bother?
What's the point of removing the cat if you're not going to pass at all? If your car wont pass, you wont be able to register your car.
Besides, removing the cat is a bit selfish. You're basically giving up a lot of harmful emissions for a few ponies that you probably wont utilize on your daily drive.
Pro's- gain a few ponies
con'- everything else to it
Definitely not worth removing the cat. The consequences cannot be over come by the benefit (if any).
Besides, removing the cat is a bit selfish. You're basically giving up a lot of harmful emissions for a few ponies that you probably wont utilize on your daily drive.
Pro's- gain a few ponies
con'- everything else to it
Definitely not worth removing the cat. The consequences cannot be over come by the benefit (if any).
Lexus Champion
Joined: Oct 2006
Posts: 2,175
Likes: 1
From: AFGI
Technically, maybe on a 2GS you will gain 3-5 HP. But on other cars that have a ton of money invested in the motor, you will see more of a significant gain. I'm not sure what the smog laws are in Maryland, but in CA they are stupid restrictive. Many vehicles did not come equipped with cat's until the 80's. Despite this fact, CA has exacted and passed a law that states that vehicles 1976 and newer need a cat. Only vehicles 1975 and older are exempt from not using cat's. People like my father who own cars such as the first gen RX-7 that were built in the late 70's get screwed over.
BTW, there was/is legislation to enact this law nationwide.
I would have to disagree with both of you, it is not greedy to not use cats. Its stupid for states to pass laws restricting vehicles that did not come with cats in the first place to now need them.
BTW, there was/is legislation to enact this law nationwide.
I would have to disagree with both of you, it is not greedy to not use cats. Its stupid for states to pass laws restricting vehicles that did not come with cats in the first place to now need them.
I wouldn't run with no cats due to pollution. The cat is there for a reason. However, replacing them with a high flow cat would be better than running with none at all. There's a video where Top Secret did a test with and without a hi flow cat on their Skyline, if I remember correctly. With the cat, they only lost 7 hp but significantly reduced the amount of harmful emissions. (I can't find the video online but maybe someone else can).
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Chris, although I do wish Cali laws weren't as strict, we really need the catalytic convertors, especially since we live in a smog-congested area. The emission is just not worth the extra ponies if it means I'll be breathing in a lot of junk. A hi-flow cat would probably be the good balance between running the OEM cat and no cat at all.
If I had a car that made 300whp with no cat, and then slap on some cats to only dyno 280whp, I would respect that number a lot more. By all means I'm not a tree-hugger, but I rather not take my chances on the poisonous carbon monoxide gas. I have to let my blood transport oxygen
If I had a car that made 300whp with no cat, and then slap on some cats to only dyno 280whp, I would respect that number a lot more. By all means I'm not a tree-hugger, but I rather not take my chances on the poisonous carbon monoxide gas. I have to let my blood transport oxygen
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Thread Starter
Pole Position
Joined: Oct 2004
Posts: 3,397
Likes: 14
From: Maryland
Thanks for the feedback, fellas. Keep 'em coming. If it's not a significant gain, I'd rather not stink up the air with more pollutants. I'll just wait 'til spring and get the headers.
Damn, I forgot the stall speed. I got it from SRT a few years ago, so it was whatever one he was using at the time. I dont remember the name or the stall speed.
And all I need is your address and I'll send you my latest mixes.
By the way, Lex, how do you like your headers? Significant mid-level gains on the highway?
And all I need is your address and I'll send you my latest mixes.
By the way, Lex, how do you like your headers? Significant mid-level gains on the highway?
GSTeg, on a high power turbo car(400hp-ish) having a cat can cause up to a 40-50hp hit in horsepower figures. Pretty soon, with me pushing past 600hp the cat in place will cause an even bigger restriction in power. I'm all for cleaner air so that's why I'm gonna install a high flow cat...well when I have the money to do so(a high quality highflow isn't cheap) lol . I also have the electric dump so I can just open up the exhaust when I need maximum power. Then when I'm cruising I can close the dump and drive around and be ok with a big hp loss
. I also have the electric dump so I can just open up the exhaust when I need maximum power. Then when I'm cruising I can close the dump and drive around and be ok with a big hp loss
My car wont pass MD emissions because of my check engine light being on with the TC.
So, I'm figuring if I'm not gonna pass ANYway, why not go ahead and just remove the catalytic converters?
I have the Tanabe MT Exhaust, and the SRT intake. What are the pros and cons of having no cats? Is there any performance gain at all? Should I even bother?
So, I'm figuring if I'm not gonna pass ANYway, why not go ahead and just remove the catalytic converters?
I have the Tanabe MT Exhaust, and the SRT intake. What are the pros and cons of having no cats? Is there any performance gain at all? Should I even bother?
If it takes awhile for it to come on you might get it cleared just prior to getting your emissions test.
I understand the power loss on a high powered car, but we're talking about mostly stock cars here 
I've been around cars long enough to know what part does what. Then again, maybe the hefty $10,000 fine in cali makes most tuners here not want to remove their cats . I hardly see any high-powered cars here running catless system. It's mostly the stock-ish Honda EG-hatches who takes off their car
Simply not worth it on a normal GS
I've been around cars long enough to know what part does what. Then again, maybe the hefty $10,000 fine in cali makes most tuners here not want to remove their cats . I hardly see any high-powered cars here running catless system. It's mostly the stock-ish Honda EG-hatches who takes off their carSimply not worth it on a normal GS
Last edited by GSteg; Oct 9, 2007 at 07:44 AM.
Lexus Fanatic
Joined: Sep 2005
Posts: 5,095
Likes: 9
From: The Rotten Apple
Hey Kev. I removed my cats originally and I just couldn't bear the smell on a regular. Especially with all the stop and go traffic here in NYC. I eventually put a high flow cat and it made a world of difference in the way it smells, LOL.
Like GSteg said if anything just switch to a high flow cat.
Nick, the point of hollowing out your cat is to pass visual inspection. Your basically gutting out the cat which is the same thing as removing them.
For those interested, I went with the magnaflow 3" high flow cat. I got it for under $80 shipped. They have EPA compliant & CARB certified OBDII Catalytic Converters up to 3" inlets.
You can get them from www.hottexhaust.com. They are also having some sale going on where all items are discounted 10.5%. They offer free shipping on orders over $50, no sales tax and here's the coupon code so that you can get an additional 10% off.
At checkout use the code : hottsavings
Like GSteg said if anything just switch to a high flow cat.
Nick, the point of hollowing out your cat is to pass visual inspection. Your basically gutting out the cat which is the same thing as removing them.
For those interested, I went with the magnaflow 3" high flow cat. I got it for under $80 shipped. They have EPA compliant & CARB certified OBDII Catalytic Converters up to 3" inlets.
You can get them from www.hottexhaust.com. They are also having some sale going on where all items are discounted 10.5%. They offer free shipping on orders over $50, no sales tax and here's the coupon code so that you can get an additional 10% off.
At checkout use the code : hottsavings
Hey Kev. I removed my cats originally and I just couldn't bear the smell on a regular. Especially with all the stop and go traffic here in NYC. I eventually put a high flow cat and it made a world of difference in the way it smells, LOL.
Like GSteg said if anything just switch to a high flow cat.
Nick, the point of hollowing out your cat is to pass visual inspection. Your basically gutting out the cat which is the same thing as removing them.
For those interested, I went with the magnaflow 3" high flow cat. I got it for under $80 shipped. They have EPA compliant & CARB certified OBDII Catalytic Converters up to 3" inlets.
You can get them from www.hottexhaust.com. They are also having some sale going on where all items are discounted 10.5%. They offer free shipping on orders over $50, no sales tax and here's the coupon code so that you can get an additional 10% off.
At checkout use the code : hottsavings
Like GSteg said if anything just switch to a high flow cat.
Nick, the point of hollowing out your cat is to pass visual inspection. Your basically gutting out the cat which is the same thing as removing them.
For those interested, I went with the magnaflow 3" high flow cat. I got it for under $80 shipped. They have EPA compliant & CARB certified OBDII Catalytic Converters up to 3" inlets.
You can get them from www.hottexhaust.com. They are also having some sale going on where all items are discounted 10.5%. They offer free shipping on orders over $50, no sales tax and here's the coupon code so that you can get an additional 10% off.
At checkout use the code : hottsavings
I always wanted a nice hi-flow cat...I'm gonna check that out...Thanks