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Removing Cat Converter

Posted: March 7th, 2002, 8:09 pm
by Chacha
I have a 94 MX3 GS, and I wanna remove the Catalytic Converter, I was wandering, If I would lose power or torque if I do this, I know it'd be louder and "toxic" chemicals would be realese but how about power and torque?<BR>thanx [img]shrug.gif"%20border="0[/img]

Re: Removing Cat Converter

Posted: March 7th, 2002, 8:28 pm
by SmokyMcGee
i took mine off, it sounds more raspy, but not too loud. As for power... Im assuming it gives you somewhat power by be less restrictive with the exhaust..

Re: Removing Cat Converter

Posted: March 7th, 2002, 9:23 pm
by Chacha
Thanx for the info bro, but Did u feel loss of torque or anything?

Re: Removing Cat Converter

Posted: March 7th, 2002, 10:20 pm
by mitmaks
u would lose torque on any car if u remove piping or part of piping that is ment to be there

Re: Removing Cat Converter

Posted: March 7th, 2002, 11:39 pm
by pelado
Mitmaks, I doubt that the torque is "lost." The torque curve might shift to peak at a higher rpm.

Re: Removing Cat Converter

Posted: March 8th, 2002, 12:06 am
by Bri94GS
I hollowed out my catalytic converter, and i notice a little gain, but not much. Unless you have an aftermarket exhaust, it's not really worth doing. I almost failed all 3 sections on emissions as well.

Re: Removing Cat Converter

Posted: March 8th, 2002, 1:12 am
by Chacha
so, if I take the Cat Conv. out and replace it for a straight thru pipe, that'd affect torque, would I feel a big loss? would I fail all emission tests? [img]shrug.gif"%20border="0[/img]

Re: Removing Cat Converter

Posted: March 8th, 2002, 1:18 am
by Bri94GS
if you took the cat completely off, you'd probably fail. I know here in CT, they look under the car with a mirror to make sure there is a cat on there. Mine is there, but i hollowed it out (it's filled with this stuff that looks like a ceramin honeycomb)...i still almost failed...do you know what the emission limits are where you live? You should check, and then ill post what my car ran

Re: Removing Cat Converter

Posted: March 8th, 2002, 5:49 am
by Guest
my cat was plugged so i punched it out and ya it sounded cool but its hard on the motor if u have your whole exhaust done. no back pressure on the valves = not good! and ya i shot flames shifting second to third hard! so ya its cool but bad for your motor get a high flow cat if u want to open up your exhaust more

Re: Removing Cat Converter

Posted: March 8th, 2002, 9:21 am
by DAC 752
Around here its illegal to not have a cat on a car that is newer than '91 if u take your cat out and keep your o2 sensor then it should be fine but if u loose the o2 sensor the gas mileage will go down alot

Re: Removing Cat Converter

Posted: March 8th, 2002, 1:25 pm
by endocyc
Hey, if you are serious about taking out the stock CAT you really should replace it with an aftermarket high flow CAT. Its better for the engine/enviroment and like the other guy said its an automatic failure for the drive clean. A cheap high flow should only cost around $100 cnd.

Re: Removing Cat Converter

Posted: March 8th, 2002, 1:33 pm
by OsoSlo z28
backpressure is bad. that's why if you do something to your motor to give it more power(more air in, more exhaust out) you upgrade your exhaust to a bigger diameter. you want to relieve backpressure and maximize your exhaust gas velocity....that's why too big of a pipe is bad also. the only thing you are hurting is the environment. that's why a lot of off-road race cars have the cat removed...not street legal, but increases exhaust flow<p>[ March 08, 2002: Message edited by: cre8v mx3 ]

Re: Removing Cat Converter

Posted: March 8th, 2002, 3:01 pm
by Bri94GS
backpressure isn't bad on small motor/low HP cars. If you don't have any backpressure, you'll lose almost all low end torque, and the car will lag. Try running your car with no exhaust on it if you want an explaination. The only time it's good to have really low backpressure is with boosted cars....i don't see how your car would shoot flames without a cat....anyways, here's my kitty...<BR> Image<p>[ March 08, 2002: Message edited by: Bri94GS ]

Re: Removing Cat Converter

Posted: March 8th, 2002, 5:23 pm
by pelado
For anyone that's wondering (or cares) it is illegal in the USA for ANYONE to remove their cat AND drive it on the street. I don't think anyone is being aggressively prosecuted for this but I vaguely recall that the fines are pretty hefty. A hefty fine can also be levied upon any professional mechanic or shop that removes a cat and replaces it with a "test" pipe.<P>So if you're thinking about removing your cat, you should also think about replacing it with a high flow cat instead of using a test pipe.

Re: Removing Cat Converter

Posted: March 8th, 2002, 8:10 pm
by blikmik
Hey chacha.. you're from Calgary? Is your car insured right now?.. If so , then what are you worried about failing emissions for? we don't have mandatory testing here.. anyways..the guys are right in saying to get a high flow cat - why do you wanna do this anyways? Is your car requiring flow?