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Old 10-31-2012, 04:17 PM   #1
slimshade1
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Default Good idea or bad idea?

Is it a good or bad idea to take my cats off. I just dont want them anymore i dont need emissions where i live. i have 188xxx miles and the only mod i have is a magnaflow axle back
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Old 10-31-2012, 04:26 PM   #2
Hoon Goon
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Environmentalist: Leave them on. Save the trees.

Hoon Goon: Ditch them, but keep them in a safe place in case you need them for inspections years down the road. OEM replacements are $$$$$.

Note: This is bad advice. Leave your emissions equipment alone. EPA is your daddy and knows best.
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Old 10-31-2012, 04:43 PM   #3
slimshade1
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Quote:
Originally Posted by Hoon Goon View Post
Environmentalist: Leave them on. Save the trees.

Hoon Goon: Ditch them, but keep them in a safe place in case you need them for inspections years down the road. OEM replacements are $$$$$.

Note: This is bad advice. Leave your emissions equipment alone. EPA is your daddy and knows best.
i dont have emissions where i live
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Old 10-31-2012, 06:34 PM   #4
yarrgh
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No emissions in Gilbert? I could have sworn I had to when I lived there...over 10 years ago. Either way, running sans cats would be louder, so there's that to consider. Some say you won't notice any power gain. You could give back to the community and do some dyno tests.
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Old 10-31-2012, 06:41 PM   #5
cal_look_zero
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If you eliminate the cats, you'll need a track pipe and a resonator. If you just knock out the catalyst element, you'll create an expansion chamber and lose hp.

I tried a track pipe, and it through off how my car ran (already heavily modified) so I opted to not run it until i can get a tune.
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Old 10-31-2012, 07:07 PM   #6
chazly413
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It just seems like a lot of work for a whole lot of nothing, as in no real power benefits.

I also hate the smell of catless
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Old 10-31-2012, 07:35 PM   #7
slimshade1
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Quote:
Originally Posted by yarrgh
No emissions in Gilbert? I could have sworn I had to when I lived there...over 10 years ago. Either way, running sans cats would be louder, so there's that to consider. Some say you won't notice any power gain. You could give back to the community and do some dyno tests.
I just moved to heber overgaard and haven't updated this yet
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Old 11-01-2012, 04:00 PM   #8
travis175
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if you have no need for them where you live, then do it man
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Old 11-01-2012, 09:14 PM   #9
Foenetik
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Honestly, if you have stock piping diameter your really not going to gain much. Yes youd free up some flow but your still going to be restricted overall by the oem piping size. I dont personally feel its going to justify the cost of replacing them with straight pipe for the little gain youd get.
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Old 11-01-2012, 11:38 PM   #10
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Quote:
Originally Posted by Foenetik View Post
Honestly, if you have stock piping diameter your really not going to gain much. Yes youd free up some flow but your still going to be restricted overall by the oem piping size. I dont personally feel its going to justify the cost of replacing them with straight pipe for the little gain youd get.
Have you ever seen the inside of a catalytic converter..? There's more than "some" airflow to be freed up there...


Do it. I replaced my 2nd and 3rd cats with 2.25" piping and my lower end definitely increased just enough to notice.
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Old 11-01-2012, 11:43 PM   #11
EvileyeZ88
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Just knocking the cats through will decrease HP and Gas mileage
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Old 11-01-2012, 11:46 PM   #12
cal_look_zero
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Quote:
Originally Posted by KelConquer View Post
Have you ever seen the inside of a catalytic converter..? There's more than "some" airflow to be freed up there...


Do it. I replaced my 2nd and 3rd cats with 2.25" piping and my lower end definitely increased just enough to notice.
Subaru cats flow surprisingly well for OEM. Plus, it's not like the stock engines produce THAT much flow that the cats are prohibitive.

I'm sure anything helps, but it's like tucking for aerodynamics on a Vespa scooter.
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Old 11-01-2012, 11:51 PM   #13
chazly413
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Quote:
Originally Posted by KelConquer View Post
Have you ever seen the inside of a catalytic converter..? There's more than "some" airflow to be freed up there...


Do it. I replaced my 2nd and 3rd cats with 2.25" piping and my lower end definitely increased just enough to notice.
Yes, I'm sure the engineers who designed the exhaust system completely disregarded that honeycomb in their design parameters.

I agree with you if we're talking about adding a good bit of power, but it's designed to flow with minimal restriction for a stock system.
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Old 11-02-2012, 01:17 AM   #14
Foenetik
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Quote:
Originally Posted by KelConquer

Have you ever seen the inside of a catalytic converter..? There's more than "some" airflow to be freed up there...

Do it. I replaced my 2nd and 3rd cats with 2.25" piping and my lower end definitely increased just enough to notice.
Oh. You got me. Never saw the inside of one. Your probably right then.
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Old 11-02-2012, 02:27 AM   #15
Counterfit
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Quote:
Originally Posted by cal_look_zero
I'm sure anything helps, but it's like tucking for aerodynamics on a Vespa scooter.
Hey, if it works on a Trek...
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Old 11-02-2012, 03:03 PM   #16
Patrick Olsen
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My vote is bad idea.

(1) There will be little to no gain in performance.
(2) Your exhaust will stink.
(3) You'll trigger a cat efficiency CEL.
(4) While there may not be a local requirement for emissions testing in your area, your car is still required to have emissions equipment on it. That's a federal requirement courtesy of the EPA. Cats that are no longer functional or are missing are (per the EPA) required to be replaced with an equivalent cat. Moving to a new location doesn't change that federal law.
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Old 11-02-2012, 03:16 PM   #17
Matt Monson
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An Ej22 with 188k mi on it? You'll gain back maybe 2hp, and that is if you do it properly with all new piping. You won't even feel the difference.
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Old 11-02-2012, 03:30 PM   #18
slimshade1
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i was told its a good idea on rs25....
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Old 11-02-2012, 05:12 PM   #19
Patrick Olsen
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Well then, that settles it. Chop those bitches out!
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Old 11-03-2012, 10:53 PM   #20
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It will be more responsive without the cats and you will gain a little fuel mileage but it could mess up your tune.
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Old 11-04-2012, 03:44 PM   #21
slimshade1
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Quote:
Originally Posted by mod maniac View Post
It will be more responsive without the cats and you will gain a little fuel mileage but it could mess up your tune.
so ill just have to get it retuned??
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Old 11-06-2012, 02:57 AM   #22
Eyedoc Orlando
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$400,000 fine = bad idea

Cats dont reduce power these days, leave them on
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Old 11-06-2012, 10:33 AM   #23
EvileyeZ88
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Tune??? On a na with 188k????

Just leave the cats in place, your going to cause yourself more headaches than its worth.

I had to remove the cats from my system on my 99 obs because they were disintegrating, rattling and shooting out the tail pipe.

I even did the spark arrestor trick to defeat the cel

After doing so I noticed decreased gas milage, the car felt more sluggish, sounds like Ass, and stinks to high heaven.

The only way to get a better sound and more power is to have an UEL header fabbed up (sound) and have a custom header back exhaust made (power)

If you want power you got the wrong car for it. You need turboZ
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Old 11-06-2012, 11:05 PM   #24
Blase M
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Cat-less will be loud and smelly. Probably not worth it on your 2.2. However, if you do it right, with stainless steel exhaust manifold and the cat section (either track pipe, or high flow cat), you'll at least have an exhaust that will outlast the rest of your car...
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Old 11-20-2012, 10:34 PM   #25
Elmerfudgeboost7
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If you take off your cats your killing penguins, what did they ever do to you?
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