[GEN III]Is deleting/gutting rear cats worth it for increasing sound?

[AbsolutHank]

A full Belanger exhaust setup is in my future, so for the time being, I don't want to invest in high flow cats. How much will the overall volume be increased by removing or gutting the rear cat? If it's not worth the hassle, then I'll leave it be. I'm just getting itchy for some more sound, cause my Corsa just isn't doing it for me anymore!

Would the foot box heat be noticeably lower too, or is that primarily eliminated with high flow cats?

 

[Rizzo]

I have no cats and an 08 exhaust. Sounds great at high rpms. Way cooler at the side of the car and less heat inside. I don't notice any smell at all. I take the cats out of every sports car I have ever owned. It will louder for sure without cats. They do kill the sound for sure. As far as hp you won't gain much. 3 to 5 is what I've been told.

 

[Barrels]

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I have no cats and an 08 exhaust. Sounds great at high rpms. Way cooler at the side of the car and less heat inside. I don't notice any smell at all. I take the cats out of every sports car I have ever owned. It will louder for sure without cats. They do kill the sound for sure. As far as hp you won't gain much. 3 to 5 is what I've been told.

All this is true, except for the last part. I have a 3" mandrel-bent cat-delete and GENIV cat-back in my 03. The only other HP related adds I have are a K&N and BBK Throttle body. The blue line in the graph below is the dyno pull with the mods but before the dyno-tune. The red line is after the tune. I know dyno numbers are far from exact, but I feel confident saying that deleting the stock cats will get you more HP and torque than a header/high-flow cat setup. That's based on my experience and all the research I did on this and other viper forums before I made the switch. But even if I am wrong on that assertion, I think there is no question that the cat-delete is the best bang for your buck power mod, and is perfectly drivable and non-stinky if you tune it afterwards.

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[Barrels]

I just realized my last post doesn't really answer your question since you were only talking about deleting one cat. There are a bunch of threads about that if you search. I think most people have said it works fine. The downstream 02 sensor shouldn't be affected since it is located between the two cats, but some people have said it still throws codes.

 

[2easy]

I have done this on my 03. I gutted the secondary, deleted the crossover pipes and added an 08 side exhaust system. It works great. It is way louder all around. Since the second O2 sensor is between the primary and secondary cats, which is downstream of the primary, and you are only gutting the secondary, you will not throw any CEL light or codes. The cab is much cooler as well. This is a great upgrade for a minimal cost. Good luck

 

[cubican]

Deliting the rear cat will give you the sound your looking for, and no drone using the corsas. Great mod.

 

[AbsolutHank]

So you just remove the mufflers, and go up in there with a screwdriver/chisel and beat the inside out?

 

[2easy]

Well you can. Pull them off the car first, and use a big driver or a sharpened metal rod with a hammer and work away at it....I dont have that kind of time so I did neither. I went to Home depot and rented a large electric jack hammer with an 18 inch chissel bit. I worked the gun with the bit on from just the impact setting to the rotating setting. You use the impact setting to cut all the "honeycomb" out, and as I cut I found many of the pieces too big to come out of the end of the pipe so I would go back and forthe from the impact setting to the drilling or rotating setting to grind up the pieces small enough to fall out the end of the pipe. It took about 10 minutes per side. I would guess it would take you all afternoon with a screwdriver per side. If you have enough cold beer I guess it could be achieved that way.

 

[SlayerLS1]

Let me know when you end up working on your exhaust...whether its this or the aero catback, etc. I'm happy to help.

 

[swexlin]

I have the Mopar Race exhaust on my 2003, and while it is loud, it is not obnoxious. I lke it.