Chopping off the cat.

I've got a 2001 WS6 that I bought with headers, y-pipe and a muffler.  It currently has one cat left on it and I was wanting to know if I could just chop it off.  Would I need to invest in some different O2 simulators, tweak something, or is it already to go as is?

You can remove it but you will need either O2 sims or to have the PCM reprogramed.

Why? As I've heard before...


"Leave the poor cat alone!" 

You're really not going to gain anything from it besides not passing emissions.

No wait! I remember a certain guy on the forums that "gutted" his cat on his V6 camaro and it beat a Dodge Viper STR-10. So lemme think...

160 hp stock camaro

600 hp stock viper

So he got over 500 horses from gutting the cat! I'm sure more older forums members will remind me of this guys name and...LOL...his stories.

Yeah, but he didn't remove the cat, & gutted it. You need a gutted cat to make that sort of power. Can't just remove the cat. LOL

quote:

ORIGINAL: z28pete

Yeah, but he didn't remove the cat, & gutted it. You need a gutted cat to make that sort of power. Can't just remove the cat. LOL

rofl thats not ever going to die.

LOL, I knew people would remember! :D Gut the cat and you'll get like low 9s on the drag...hell...maybe even 8s!

Passing emissions is the least of my worries.  I live in Decatur, Illinois.  It's this ****ty industrial town, highly polluted and they never check emissions, that's on the verge of death, basically the asshole of the midwest.  The only reason I ask I that I simply want my exhaust to be free flowing as possible and I figured if I could get away with just chopping the ****er off instead of buying a high flow cat, then all the better.

Seriously, the cat isn't that restrictive, besides some engines will LOSE power if they don't have at least SOME back pressure. 

Keep in mind that I said some engines.

When you say some engines is there any real way to tell?  When I had my 78 Z28 and chopped off turbo's I had it actually gained horsepower, power I could actually feel, despite the fact the people were telling me it wouldn't have enough back pressure.  A buddy of mine eliminated the cat and muffler on a LT1 of his and noticed a lack of power towards the lower RPM band but gained some in the upper, so once again, do you know of any way to determine what would be best for my car?

gut the cat. meow.

A good modern style cat in good condition, and of the proper size should create very little restriction or power loss. An old style cat (pellet type) or a modern one that is in poor condition will create a noticeable power loss. A totally messed up cat can cause the engine to choke on itself and even stop running. IMO most people that state they experienced a noticeable power gain by removing the cat, had a bad cat to begin with.

When I bought the car the exhaust had already been done, with one cat left, the others eliminated.  As far as I know it is still fine, however it is a little banged up from bottoming out.  While it's just slightly caved in in a few places, will this make an noticable losses in power?

If it got banged up there is a chance that the stuff inside got crumbled up and blown out the exhaust. You may just have a gutted cat in your possession, LOL

why not just get a high flow cat?  they seem pretty cheap and increase airflow by like 80%

because a gutted cat increases airflow by 300 %