[PackersFan26]

Originally Posted by TrickracenLS3

in CA, long tubes are also illegal, if you're gonna do it, do it right and get rid of the cats too.

are they really??? i had no idea about this.

[marknagy13]

Originally Posted by PackersFan26

are they really??? i had no idea about this.

Yup you cannot touch the cats at all in California. Has to pass a visual test

[SilverSixGen]

Hmm, I think I'm gonna go ahead and get the catted version. I don't have to pass emissions in my county so that was never really a worry nor was the performance gains. I was just curious as to which would sound better with a x pipe and catback. Possibly corsa, borla s type, or borla ATAK.

[Megahurtz]

Catted. Negligible power loss with today's technology. Keeps the car from having rich exhaust fumes which I find annoying.

[aka Reckless]

I was going to go with CATs until I decided to go FI and make serious power. Seems the CATs can be an issue at some point. I run E85 and it's not smelly at all

[Atomic Ed]

Originally Posted by 2SS_in_GA

I was going to go with CATs until I decided to go FI and make serious power. Seems the CATs can be an issue at some point. I run E85 and it's not smelly at all

FI setups are making well over 700 rwhp with the stock exhaust. Can't see CATs being an issue unless you plan to approach 750+ rwhp.

[mariojmoe]

Originally Posted by 2SS_in_GA

I was going to go with CATs until I decided to go FI and make serious power. Seems the CATs can be an issue at some point. I run E85 and it's not smelly at all

Same here man. I'm going to be very over 720 rwhp on 93 and probably just under 800 rwhp on E. I went 2 inch lt's no cats and full 3 inch exhaust. 93/E85 mix = no fumes

[ULTRAZLS1]

FWIW Im not sure I like the sound of my catless headers into my stock NPP. Kinda raspy/tinny. On a cold start with valves open it makes a terrible high pitched raspy noise for about 5 seconds before idling down as well. I been keeping the car in tour mode sounds the best now IMO.

Ill probably end up getting the kooks full exhaust in the future.

So as far as sound...with a stock npp catted would be better. You made the right choice. And as others have said the hp difference is less than 5hp when using hi flow cats

[aka Reckless]

Originally Posted by Atomic Ed

FI setups are making well over 700 rwhp with the stock exhaust. Can't see CATs being an issue unless you plan to approach 750+ rwhp.

Exactly

[aka Reckless]

Originally Posted by ULTRAZLS1

FWIW Im not sure I like the sound of my catless headers into my stock NPP. Kinda raspy/tinny. On a cold start with valves open it makes a terrible high pitched raspy noise for about 5 seconds before idling down as well. I been keeping the car in tour mode sounds the best now IMO.

Ill probably end up getting the kooks full exhaust in the future.

So as far as sound...with a stock npp catted would be better. You made the right choice. And as others have said the hp difference is less than 5hp when using hi flow cats

I have noticed this too. I am going to look into options that might help with the tinny sound. Maybe some bullets inline or something.