Cat Cut

[-Alero-]

my friend suggested i cut my cat converter off or hollow it out, and he said it should give around 20 to 30 hp, and only costs 60 dollars to be done. do you guys think its a good idea to neautralize my cat? if so do you think i'll gain low end? mid range? or high end torque?

[Sundayalero]

Nooooooooo!!!! Save your money.

[Sundayalero]

Really, this is going to give you no HP gains. Put the $60 towards something else for your ride.

[-Alero-]

lol ok thanks, well where can i get a high flow cat?

high flow cat is worthless as well.

the stock cat is just fine.

how old are u?

For 60 bucks, HECK YEAH DO IT! I don't know what these guys are talking about, but cutting the cat out WILL increase the HP and Torque. "High-flow cat" is a waste of money. Either have it or don't. If you want to go all the way, our cars have resonators too. If you look at your undercarriage, you will see two tubes. One is the resonator and the other is the cat. Cut both of those out, straight pipe it and you WILL add some balls to your engine. My friend has done this on this Pontiac Fiero and a guy at my work has the exact same car, 86 Pontiac Fiero GT V6. My friend's Fiero, which has the cat removed, SMOKED the stock Fiero. That think jumped off the line and never looked back. Now the guy at my work is in the process of cutting his cat out. As for emissions, when I stand behind my friend's Fiero, it makes my eyes burn and you can smell the fumes. But he still passes emissions (Washington State). If an 86 Fiero with cat cut out can pass emissions, Alero with cat cut out will pass emissions with flying colors. Sure, it will be higher emission readings, but pass is a pass is a pass whether it's by an inch or a mile.
I personally am in the process of cutting out the cat. I am thinking about leaving the resonator in at the cost of HP and torque because I don't want it to sound like a muscle car. Cutting out the cat will most likely give you the Mustang GT/Cobra or Corvette sound while cutting both the cat AND the resonator will give you even more growl.
I think it's a heck of a deal to do this for 60 bucks. Well, let me know how it goes.

[jamcllw]

I think what he's(the canadian) trying to say and your not understanding is that the converters that GM puts on flow more air than our motors can move. I have to agree that removing the cat is dumb. With the cat removed you may and I say may add 1 hp above 4000 RPM.

[Sundayalero]

So your opinion... What do you think he is going to gain from cutting out the cat and resonator?

Okay, my two-cents....The stock Alero cat flows very well for a stock converter. So there is really no reason to go hacking it off. You will not gain but maybe 4-5 hp out of it. Just how good is the stock cat? There have been dyno test of a pricey ($350) high-flow cat and it only showed a 2-3 hp gain. Not worth it.

The only reason a person might consider switching to a high-flow cat in our cars is if they redid the entire exhaust system to a larger pipe diameter, then I would splurge the $75-100 to get a Catco or Dynomax high flow-cat that is the same diameter as the new pipes.

But if you wish go ahead and gut your cat. Though you are looking at expensive cost to replace it, in addition to possible fines for gutting it when you car fails an emissions test. Emissions test have different standards around the country. What may pass in one place will fail miserably in another.

Thread reopened, play nice and keep the discussions civil please. :thumbsup:

[Sundayalero]

Originally posted by Grouch@Jul 22 2004, 03:43 PM
But if you wish go ahead and gut your cat. Though you are looking at expensive cost to replace it, in addition to possible fines for gutting it when you car fails an emissions test. Emissions test have different standards around the country. What may pass in one place will fail miserably in another.

Thread reopened, play nice and keep the discussions civil please. :thumbsup:

In California they wont even test your car with out the CAT on it.

[jamcllw]

Originally posted by Sundayalero+Jul 22 2004, 03:50 PM--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Sundayalero @ Jul 22 2004, 03:50 PM)</td></tr><tr><td id='QUOTE'> <!--QuoteBegin-Grouch@Jul 22 2004, 03:43 PM
But if you wish go ahead and gut your cat. Though you are looking at expensive cost to replace it, in addition to possible fines for gutting it when you car fails an emissions test. Emissions test have different standards around the country. What may pass in one place will fail miserably in another.

Thread reopened, play nice and keep the discussions civil please. :thumbsup:

In California they wont even test your car with out the CAT on it. [/b][/quote]
Same here in Ohio.

[b-spot]

No emisisons testing here, but a big fat ticket if your found without it.

I guess if you wanna be another ricer then cut it out so you get a louder sound for revvin at stop lights! Lmao but its a waste of money to do anything to just the exhaust or just the intake w/out upgrading the other part...cut the cat out it wont flow more...put a CAI on and it wont give any real gains w/ stock exhaust even w/ cat cut out, gotta do both basically for gains....hope that helps some

[Redog]

He in Philly if you have no CAT the car won't pass emissions, as part of Northeast Emissions, but you can do a high flow but don't go too big. It will rob HP instead of gaining it.

20 to 30 HP from hollowing a cat is BS. In fact, even if you remove a cat those numbers are BS. The guy either doesn't know what he talking about or he's trying to rip you off.

Just look at the numbers. A SPL or a Borla cat back will add only about 11 HP. The only way to get 30 HP out of exhaust is to put on headers too. Then your up around the 30 HP range. But this is all a lot more than $60 too. About $600 for the exhaust and $700 to $800 for the headers.

[bdyman]

grouch is right the stock cat flows really well and no need for a high flow at all
save your money and put into something else

[mdodge]

I agree with all. Not sure if this statement is accurate...but I heard that when you remove the cat....you gain 1mph for every 100mph. Woopdeee freakin doo daa daay.

It' a BIG no no for anyone in Canada, Even here in Labrador ( Where they don't even do emmissions testing ) if you get caught without one, your car will be pulled off the road........ I've seen a cop get under and tap on the cat to make sure it wasn't empty.... (Of course the cop was just looking for violations because the guy i was riding with was mouthing off at the cop.)

I wouldn't bother...

N8tureboy

We don't have emissions testing in IL, but if you're caught w/o a cat, you can get a very heafty fine. No exhaust shops around here will cut off a cat or even install a high-flow cat w/ an o2 simulator because it is illegal. I can't imagine a shop actually allowing a customer to come in and pay $60 to have theirs "hollowed out". If you have exhaust laws in your state, that shop could get fined hardcore if they did a job like that to a car that drove up. Only time they can do that stuff is if it's trailered up and trailered back because it's for off-road use only.

[mike2002]

its not illegal IF the car is 5 years old or 60,000 miles.

highflow cats are good on old cars, when they made cats differently, id only change it if your doing the whole exhaust, or if you damaged your oem cat somehow (highflow's are cheaper thean oem)

there are hundreds of variables why 1 fiero is faster than the other, besides thats oranges to apples.

oh, and the fine, is like $10000 or maybe it was $20,000...pass emissions or not pass or even if you dont have emissions in your state, like me in minnesota, if you get caught without one, your hosed.

[mike2002]

its not illegal IF the car is 5 years old or 60,000 miles.

highflow cats are good on old cars, when they made cats differently, id only change it if your doing the whole exhaust, or if you damaged your oem cat somehow (highflow's are cheaper thean oem)

there are hundreds of variables why 1 fiero is faster than the other, besides thats oranges to apples.

oh, and the fine, is like $10000 or maybe it was $20,000...pass emissions or not pass or even if you dont have emissions in your state, like me in minnesota, if you get caught without one, your hosed.