HELP!!! Should I Gut the Cat???

Kent Buckles

BBBAAD 6
Joined
Feb 8, 2002
:confused: I need a few opinions on this! I bought my GN without a Catalytic Converter. I later added a 2 1/2" Hooker Exhaust System along with a 3" Downpipe and 3" High Flow Cat Converter. I did not notice a big difference in performance or sound with the changes. I am assuming that what I may have gained by having a bigger downpipe I lost due to more restrictions with a Cat Converter.
My question is how would the performance, sound, turbo spooling, lag, etc... be effected by gutting out the Cat??? Is it worth it??? Any negatives other than the law possibly knowing! I would rather leave the converter on there since I do alot of cruising and street racing and do not want trouble with the local law!
THANKS in advance for anyones help or suggestions.:)
 
Gut IT!!!...or just order a "test pipe" from ATR www.atrperformance.com it's like $50-$60 and you can just switch back and forth whenever you want! I noticed a big difference w/ a gutted cat, but if I had it again, I would order the test pipe...

my $.02.
 
gut it that way if you ever get pulled over, then they can physically look at it ,and it still looks like a kitty cat
hth
 
Originally posted by Quick6'n'-K.C.
gut it that way if you ever get pulled over, then they can physically look at it ,and it still looks like a kitty cat
hth

exactly! a cop sees a test pipe bye bye car(maybe) if they see a cat they won't think anything of it..
 
Originally posted by fly89gta


exactly! a cop sees a test pipe bye bye car(maybe) if they see a cat they won't think anything of it..

Damn what state do you live in?!? If a cop were to actually look in florida (very unlikely), it's just a fix it ticket. You can say "I bought the car used. I had no idea it was illegally modified."

Florida is just a lax state for emissions. We have no inspections, and I've yet to see a cop check for cats. I was pulled over in my LS1 for it being loud and the cop didn't check for cats, he just told me to buy a new muffler. (yeah right, he can kiss my ass).
 
I replaced my working cat, kept it for smog test, and installed a stock cat that I bought on the board after I gutted it.

I did feel a big difference.

So as far as looks go, its 100% stock.
 
I believe that you can check for excedssive back pressure in the exhaust by putting a guage in where the 0-2 sensor. Shouldn't read over 7 pounds, I believe. I had a cat plug once. Maybe from running too rich. It lost boost until I could get only 4 lbs out of it. Gutting fixed it. In your case, you might as well leave things alone. Plenty of guys running great times through full exhaust. For most of us, the stock exhaust takes very little away, IMO. Those that went to larger exhausts, and saw a huge gain prolly had an ubstruction somewhere.

Check this out. Through full exhaust!! http://www.turbobuick.com/forums/showthread.php?threadid=17878&referrerid=259
 
NJ and PA, at the very least its a $1000 fine and u can lose your car till u get one put on, now the cop has the option to do that..its happened to people i know in both states :(
 
THANKS EVERYONE FOR YOUR OPINIONS! I THINK I MAY GO AHEAD AND GUT IT. I HAVE A TEST PIPE BUT I AM INDEED WORRIED ABOUT THE LOCAL POLICE AND THE CAR APPEARING TO BE LEGAL. I JUST WANTED TO MAKE SURE IT IS WORTH CUTTING UP A NEW CAT AND IF THE PERFORMANCE GAINS WOULD BE NOTICABLE. THANKS FOR ALL YOUR HELP!!!:)
 
Originally posted by fly89gta
NJ and PA, at the very least its a $1000 fine and u can lose your car till u get one put on, now the cop has the option to do that..its happened to people i know in both states :(

I requested the language from the NJ DEP. At that time, the fine only applied to shops that illegally modify or remove a cat. That was about 3 years ago. As far as I could tell, there was no fine for individual auto owners. Your penalty is not being able to pass emissions. I'm not even sure if NJ has a visual cat inspection. They slide a mirror under the car, but I was told it was to look for structural rust.

Jim Testa would know the actual rules and may prove me wrong (he has a license to inspect in NJ)....but from what I understand he's been able to get his TR to legally pass NJ emissions without a cat.

Jim
 
turbojimmy, it happened to a friend of mine, he was fined $1000, maybe it was a EPA fine, not sure

i'd also LOVE to know how someone can pass NJ emissions without a cat!!! am i missing something? any tricks or is Jim bribing people?? :D ;)
 
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