# Removing the CAT for performance?



## GoatingAround (Mar 3, 2010)

I just bought my 05 GTO, it only has 9,700 miles, and I'm already itching to do some work to it. I was rotating my tires at my friend's race shop/garage, and while speaking to the shop owner about modifications to make it faster, he mentioned taking off the CAT. Has anyone done this to their GTO, pros/cons? Thanks for the help.


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## 6point0 goat (Aug 1, 2009)

you wont pass smog but youll gain some decent performance with suporting mods, if the popo catch u without them, its like a $1000 ticket, YIKES!! id go with high flow cats/mids that way u get some performance and still have a shot at passing smog


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## GoatingAround (Mar 3, 2010)

*Correction in Title*

The shop owner said he would recommend removing the cat and inserting an X-pipe instead. I've been online looking at the Corsa Sport CatBack exhaust and it has an x-pipe in the package. Is that the piece that the shop owner said would be replacing the cat, or does that x-pipe connect to the stock catalytic converter?


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## jpalamar (Jul 22, 2008)

I'm running catless. Not sure how much gains there are but I'm sure there are some. If you do, it isn't as simple as just replacing it, you will need a tuner to turn off your rear O2s or you wil lget a check engline light.


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## svede1212 (Nov 1, 2005)

a good tune will do more for you than removing the CAT


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## GM4life (Mar 18, 2007)

I wouldn't bother with the 05+ exhaust. Removing the cats nets small gains in HP, 5-10ish if that. You will also smell bad too. The best thing I would do is remove the resonator and replace it with a X or H and get some mufflers.


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## AlanSr (Jan 4, 2008)

Since the sound increase is not that much.....How much sound increase will there be?

Would it be compared to going from stock to Flowmasters

Or like going from stock and cutting off the Res.

I'm thinking about getting mine done this week, I just want to make sure it will be worth my $80.


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## jpalamar (Jul 22, 2008)

Its only a little louder, but the tone does change to be a little more raspy. My exhaust also pops more then when I had cats. If knew whwat I did now, I'd just leave them to be honest.


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## Poncho Dan (Jun 30, 2009)

Without a tune it's going to throw codes and run like ass. Spend your time/money on a more productive mod.


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## george g (Mar 26, 2009)

Just get a set of jba catless mids and get a tune for it.


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## Poncho Dan (Jun 30, 2009)

In all seriousness, if you're going balls deep into the exhaust system to yank/gut the cats, you should at the very least install shorty headers, if not LTs. Better bang for your buck there.


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## ROBSGTO (Jul 6, 2008)

Not enough gain in hp from doing this imo......maybe 5 if that probably less since high flow cats flow well.


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