Have any of you guys out there removed just the Cats off alone without changing anything else the 996 Carrera, if so how was your performance and did it make a noticable difference?

The next question I need to know did it throw off any codes or check engine lights in the ECU system. By the way I have 2001 Tiptronic not stickshift.
I appreciate any input regarding this matter

 

Yes, removing your cats will cause a check engine light. You can run O2 bung extensions and get away with it for about a month or so if that, but eventually your check engine light will come on 100% of the time. Run a high-flow cat AND muffler setup if you want to get more air out. A complete exhaust plus a high-flow intake will get you peak HP but dip a little in the middle, but flashes are available to correct this. Flash + Exhaust + Intake is the most popular route... Their are plenums, supercharger kits, high-flow filters, etc, etc... The search button in the corner will yeild more information about all of these different options then you could care to know. Happy reading.

 

i heard one without cats and OMG, sounds badass!!

 

can you still pass SMOG test when you remove the cats or even with high flow cats ?

I am in Texas and they have those emission test..arghh

 

Most high-flow cats are 50 state legal... there's some suspect stuff coming off eBay this days but any reputable tuner's cats would work fine. You will NOT pass if they look for the cats, most testing facilities I've been to weren't that strict and you might get away with it but technically, no - you shouldn't pass.