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is gutting out the cat really worth it? - 6G Celicas Forums

Topic #26237 19 posts Started by ArizonaRed
i have emissions testing where im at but i can take it down to the other county that doesnt have the requirements. gutting out the cat will make it not pass right?

-97 Celica ST-2001 Celica GTS dk blue mica 100hp per litre(GOT LIFT?)
yes... and you'll be polluting the air and stuff too... power gains are just about nil... and you'll have a constant CEL cause your car is OBD2...

This post has been edited by Kwanza26: Jun 24, 2005 - 4:34 PM

"It's ok to be naked girl... I'm an artist!"1995 AT200 Celica ST:stocked out daily driver...1984 AE86 Corolla GT-SR5:silvertop 20V 4AGE project car jacked up with goodies...1991 SW2x MR2 n/a:bare bones hardtop model soon to be...
-Kwanza26+Jun 24, 2005 - 9:34 PM
QUOTE(Kwanza26 @ Jun 24, 2005 - 9:34 PM)
yes... and you'll be polluting the air and stuff too...  power gains are just about nil... and you'll have a constant CEL cause your car is OBD2...
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wrong i have obd2 and have a gutted cat and no CEL light for me. but even if it did come on you just have to sodder in some MIL Eliminators.
Same here, I believe it's because the O2 sensor is in the header, the only reason my light is on is the lack of a MAS.
Not only does it not help, it messes up the airflow because of all the disturbance caused to the air, and it's also very illegal.

-Doc

-Dr Tweak, 6GC's resident engine swap wiring expert extraordinaireClick here to see my swapsdrtweak@phoenixtuning.com
-Kwanza26+Jun 24, 2005 - 4:34 PM
QUOTE(Kwanza26 @ Jun 24, 2005 - 4:34 PM)
power gains are just about nil... [right][snapback]304376[/snapback][/right]


Unless you have a forced induction application...

QUOTE(lagos @ Jul 10, 2006 - 1:55 PM) [snapback]454118[/snapback]i know your trying to do the right thing for your motor, but this is one of those times where you should just trust the guys who have had their swaps for a while and have done a ton of research into this.
I recently did this to my 94 GT(5sfe). It has the cat in the exhaust manifold. I noticed minimal gains. I did it just to be doing something. If you feel like doing something, it's not that bad. But don't expect much power gain. And it is significantly louder, if that bothers you.

Live Free, Be Happy
before i gutted it out my friend with his 98 integra ls basically stock bedised exhasut and intake we raced and he beat me by a lil but then i gutted my cat out and raced em again... i won that time. so it does give you a lil edge.
yeah but you never know if one of you were just shifting badly at the time, someone had a better launch, ect.

NASA/SCCA RX-7....currently under the knife92 Civic hatch B16 - Sold10th anniv RX-7 - RIPThe Slow Celica - Sold...and then crushed crushed due to street racing.Quote from Seinfeild: George's Boss reading a magazine: "People magazine's most beautiful people. Oh and a Celica...nothin wrong with that!"
Tweak is right about it being illegal, but you having a '97 the only time you need to worry is if a sniffer test is done, the gutted cat won't show up on the computer part.
-SlowCelica94+Jun 26, 2005 - 6:09 PM
QUOTE(SlowCelica94 @ Jun 26, 2005 - 6:09 PM)
yeah but you never know if one of you were just shifting badly at the time, someone had a better launch, ect.
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it was a highway race already moving.... we both just dropped down to 4th
-darksecret+Jun 25, 2005 - 4:17 PM
QUOTE(darksecret @ Jun 25, 2005 - 4:17 PM)
Same here, I believe it's because the O2 sensor is in the header, the only reason my light is on is the lack of a MAS.
[right][snapback]304815[/snapback][/right]


96+ celicas have 2 o2 sensors

one right by the manifold, and one after the cat

no usdm celica with the stock motor has a MAS

also, unless the car is highly modded NA or turbo, dont even bother gutting the cat, especially if you have emissions testing

This post has been edited by 97sccelica: Jun 27, 2005 - 2:38 AM

1994 Celica GT4 WRC Edition@gt4.wrc on Instagram
Oh yeah, I forgot about that. Since you have a car '96 or newer, you will get a check engine light because the second 02 sensor will read no difference because the cat is gone...

-Dr Tweak, 6GC's resident engine swap wiring expert extraordinaireClick here to see my swapsdrtweak@phoenixtuning.com
is it safe to get rid of the first cat? I remember someone installing a corolla header and getting a cel light.
If it doesn't have a MAS then what is the sensor that was in the intake when I pulled off the original, looked like a MAS to me.
-darksecret+Jun 27, 2005 - 6:06 AM
QUOTE(darksecret @ Jun 27, 2005 - 6:06 AM)
If it doesn't have a MAS then what is the sensor that was in the intake when I pulled off the original, looked like a MAS to me.
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IAT

intake air temp sensor

1994 Celica GT4 WRC Edition@gt4.wrc on Instagram
for me, just have straight pipe no cat, no resonator. its noticable on the high end like on the highway, but then again as far as emissions tests go im in basackwards north carolina...who cares about pollution? lol my car is a 94 they dont even bother checking...

QUOTE (Galcobar @ Oct 15, 2008 - 2:44 AM)You want power but have no money. That's a problem.Cheap. Reliable. Fast. Pick two.
-Dr_Tweak+Jun 25, 2005 - 7:58 PM
QUOTE(Dr_Tweak @ Jun 25, 2005 - 7:58 PM)
Not only does it not help, it messes up the airflow because of all the disturbance caused to the air, and it's also very illegal.
[right][snapback]304824[/snapback][/right]


Didn't stop me.

HyperSports Racing downpipe, bin the sensors. Hello another 1.5PSI of boost, hugely improved turbo response and probably 10-15bhp.

Best £120 I've ever spent.


JDM ST205Blitz Spec NUR Exhaust, somewhere over $1000Needing another one 18000 miles later, bloody annoying.
-easternpiro1+Jun 29, 2005 - 2:09 AM
QUOTE(easternpiro1 @ Jun 29, 2005 - 2:09 AM)
for me, just have straight pipe no cat, no resonator. its noticable on the high end like on the highway, but then again as far as emissions tests go im in basackwards north carolina...who cares about pollution? lol my car is a 94 they dont even bother checking...
[right][snapback]306373[/snapback][/right]


It's just funny how NC emissions stadards are almost as bad as California's, yet SC doesn't even have any, not like the stuff is contained within the state line.