Cat bypass valve [Archive] - Forum


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03-05-2006, 05:47 PM
Has anyone successfully used a exhaust bypass around the catalytic converter? I have an SLP exhaust and i ran it stright pipe for about a week. It sounded sweet and i could tell that it was faster, but it was to loud for everyday use. The bypass is instlled in a Y-pipe and i would just use another Y-pipe to tie back in to the exhuast after the cat.

03-05-2006, 05:57 PM
Why do you need the second Y pipe? If you bypass the gas out before the cat, it would achieve the same effect as a straight pipe, without tying it back in? That way you avoid all the restriction of the muffler as well.

Also, your oxygen sensors will not be happy campers with the cutout before the cat.

03-05-2006, 06:17 PM
I still want the exhaust to come out the back of the car not under it. I like the way it sounded with the straight pipe with the SLP. I think it would be to loud to dump right under the car.

03-06-2006, 06:03 AM
Im confused as to what you exactly wanna do. You want straight pipe? As in no muff or resinator? You should have had a shop just run you straight pipe instead of buying SLP.
Hey your in K-zoo, nice, Grand Rapids here!

03-08-2006, 10:10 AM
I have had the SLP for many years now, i just want to be able to open up a path around the catalytic converter. The catalytic converter is alot more restrictive than the slp muffler.

this is the thing i want to use^

03-08-2006, 10:48 AM
Thats not really true, stock cats are actually pretty highflow. You can always buy a highflow cat also if your that concerned.
Thats a cutout and you have to mount it after the cat, there isnt enough room before it.

H.O. Driver
03-08-2006, 12:29 PM
Or you can order a o2 sim to keep the SES light off, and just run no cat, I did for many years in the state of MI, no cop ever looked under the car to see if it was there or not. I am not saying its legal to do this, but I am not saying you shouldn't either.

03-08-2006, 01:01 PM
I agree with Tim, if you live in a state like Michigan just get rid of the cat all together.

03-08-2006, 06:35 PM
dont think the extra 2hp gained from remving the cat is worth the environmental damage you will cause

03-08-2006, 07:24 PM
I did pretty much the same thing your talking about but instead of in place of the straight pipe you have i installed a dynomax resonator with a o2 simulator. The sound is more refined and hmm not as loud. But its still pretty damn loud lol

03-09-2006, 05:13 AM
dont think the extra 2hp gained from remving the cat is worth the environmental damage you will cause

The amount of people that drive in this world with cats compared to the people who have no cats is so small that the amount of camp fires burned in a year does more damage.