hey some of my friends are telling me to remove my cat. they say its legal but theyre only 15 lol. sp iwas wondering if you guys know if removing it and adding just all straight piping would help and if its legal in illinois. and also if it'll make the car louder. thanks in advance.

 

have to check your local emission laws
most places going open cat or test pipe is ILLEGAL

the performance gains are pretty noticible though.

high flow performance cat is the alternative
aftermarket high flow cats are only about 150 anyways (cheaper than stock cat)
but don't yield the same gain as open cat (yet flow better than stock though)

 

arite thanks. how much gain do u think there is? and does anyone know if its legal in illinois?

 

you can always put the cat back on every time you go for inspection

 

i had another concern that the exhaust would be louder with the cat gone but im not sure yet. does anyone know? and if it does, how much louder?

 

very loud

 

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Without a cat, cars often get that loud, whiny, raspy noise, very annoying. It is most likely illegal to remove your cat, check your local laws.

Here, my car is a 92 and is exempt from in-depth emissions tests, all the inspector does is look to make sure everything is there and "Appears to be in working order." Meaning I just have to appear to have a cat, there are ways to keep the legal appearance.

1.) You could hollow out your current cat.
2.) you could cut your current cat in half lengthways, remove the internals, and weld it onto a straight pipe to make the appearance of a cat
3.)You could just buy a high flow cat, and gain some hp, but still be legal
4.) Run a straight pipe, and just replace the cat when it's time for inspection

 

ya i just found out its legal but im jus tryin to get an idea of how loud its gonna be.

 

Expect it to be very loud, raspy, and unpleasant to the ears.

 

^depends on what kind of exhaust he has already

i have an Apexi WS2 and a test pipe and its not loud at all, just gets a little more raspy in the mid RPM range.

 

i have a greddy evo2 catback w/ stock headers

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by prelude_93vtec &raquo;</TD></TR><TR><TD CLASS="quote">i have a greddy evo2 catback w/ stock headers</TD></TR></TABLE>

anyone have taht setup that can tell me how loud itll get?

 

I have a wsp2 and a hollowed out stock cat,and its def more raspy....at first not too bad,but after aout 5-6 months it just started to rattle a lil around 3700-4000k....not too bad but annoying 2 a person as **** as me.Im getting a 2.5 high flow cat,either carsound or flowmonster(no seem welds on the flowmonster),and just having an exhaust shop weld on flanges.

Also running no cat made my car run a little bit richer for sure.

 

Add a big resonator in place of the cat and your car will sound good.