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JDMCelicaGTS
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JDMCelicaGTS Dec 23, 3:59am - #72370 
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1985 Toyota Corolla GT

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SGV*S.Ca
taking off the catalytic converter

if i take off my cat.. and run a test pipe and straight pipe my exhaust.. will i loose or gain HP? i kno i will lose back pressure so my bottom end will suck but will my ECU throw a CEL and mess up my whole overall performance?

2000 GT-S - SOLD, 12/2003
1986 AE86 GT-S - STOLEN, unrecovered, 2/2004
1985 AE86 GT-S - built 4AGTE, SOLD 10/2009
2004 Camry LE, SOLD, 5/2007-10/2007
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slidr
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slidr Dec 23, 4:34am - #72371 

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2000 Toyota Celica

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Saint Louis, MO
Dunno about performance gains or losses, but I doubt your car will pass emissions, so if you have to get that done, do it and then take it off.

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RoMkApOmKa
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RoMkApOmKa Dec 23, 4:37am - #72372 

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2002 Toyota Celica GT

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Maryland USA
And it's illegal... To much kaka will spread out from your exhaust pipe. wave

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JDMCelicaGTS
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JDMCelicaGTS Dec 23, 4:39am - #72373 
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1985 Toyota Corolla GT

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SGV*S.Ca
yeah i know that but how about the CEL and will it perform like poop because of the CEL? i was going to get a pipe made from my header-back.

2000 GT-S - SOLD, 12/2003
1986 AE86 GT-S - STOLEN, unrecovered, 2/2004
1985 AE86 GT-S - built 4AGTE, SOLD 10/2009
2004 Camry LE, SOLD, 5/2007-10/2007
1994 GS300, 2JZGTE, HKS T04Z, 10/07-Current
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RoMkApOmKa
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RoMkApOmKa Dec 23, 4:42am - #72374 

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2002 Toyota Celica GT

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Maryland USA
i Heard that you will gain some Hp if you take it off...But it's just what i heard... wink
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slidr
Specialist
slidr Dec 23, 5:04am - #72375 

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2000 Toyota Celica

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Saint Louis, MO
Originally Posted by RoMkApOmKa
i Heard that you will gain some Hp if you take it off...But it's just what i heard... wink
Yeah, and I think it weighs a few too, so it might be good for a weight reduction.

Aqua Teen Hunger Force...number one in the hood, G
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Speed4TheNeed
Caleb
Speed4TheNeed Dec 23, 5:08am - #72376 

Caleb
2000 Toyota Celica

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New Orleans, LA
Originally Posted by slidr
Dunno about performance gains or losses, but I doubt your car will pass emissions, so if you have to get that done, do it and then take it off.


it won't pass emisions..thats the whole reason for having it on there.
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Speed4TheNeed
Caleb
Speed4TheNeed Dec 23, 5:09am - #72377 

Caleb
2000 Toyota Celica

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New Orleans, LA
Originally Posted by slidr
Originally Posted by RoMkApOmKa
i Heard that you will gain some Hp if you take it off...But it's just what i heard... wink
Yeah, and I think it weighs a few too, so it might be good for a weight reduction.


you will gain...this is a big reason many japanese cars have to be "de-tuned" to come into america. emissions tests hinder performance.
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JDMCelicaGTS
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JDMCelicaGTS Dec 25, 3:58am - #72378 
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1985 Toyota Corolla GT

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SGV*S.Ca
ok.. i know its illegal and it wont pass emission but i dont have to smog it anytime soon.. and im going to have it flanged so i can put it on whenever i want.. but the QUESTION that i have is.. will it throw the CEL and will it mess up my performance?

2000 GT-S - SOLD, 12/2003
1986 AE86 GT-S - STOLEN, unrecovered, 2/2004
1985 AE86 GT-S - built 4AGTE, SOLD 10/2009
2004 Camry LE, SOLD, 5/2007-10/2007
1994 GS300, 2JZGTE, HKS T04Z, 10/07-Current
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spaztikid
dikitzaps
spaztikid Dec 25, 3:59am - #72379 
dikitzaps
1974 Toyota Celica

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LA
as long as you're o2 sensor stays in tact you should be fine.
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Speed4TheNeed
Caleb
Speed4TheNeed Dec 25, 5:14am - #72380 

Caleb
2000 Toyota Celica

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New Orleans, LA
i don't know if you cel will come on...but it shouldnt mess up your performance. should help it, actually.
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Steven
ECelica Staff
Steven Dec 25, 6:30am - #72381 
2001 Spectra Blue Mica Toyota Celica GTS
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2001 Toyota Celica GTS

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Riverside, CA
no it wont but if you keep the cel on, and you get another engine problem, you'll never know because the light will already be on. You'll have to get your codes read.

Originally Posted by JDMCelicaGTS
ok.. i know its illegal and it wont pass emission but i dont have to smog it anytime soon.. and im going to have it flanged so i can put it on whenever i want.. but the QUESTION that i have is.. will it throw the CEL and will it mess up my performance?
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DiabloGTS
Wheezy Joe
DiabloGTS Dec 25, 6:34am - #72382 

Wheezy Joe
2002 Kawasaki Ninja 250

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Lafayette, LA
I passed emissions with my kazuma exhaust on...

they didn't even hook up my car to a machine, just stuck something into the ODBII port and let me go on my way. spineyes spineyes spineyes

To have played and laughed with enthusiasm
and sung with exultation
To know even one life has breathed easier
This is to have succeeded.
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shabu
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shabu Dec 25, 6:38am - #72383 
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I haven't done this but - Your cel should come on - the second O2 sensor is there just to see if the cat is working. You would see a performance gain only IF the ecu doesn't try to tune the engine to run cleaner (probably leaner) because it has no cat!
edit - there was a post on here or ecelica on how to trick the ecu into thinking there is a cat when there isn't - if you can do that I think you would definatly see a gain!
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JBing
Pizza Geek
JBing Dec 25, 7:13am - #72384 

Pizza Geek
2002 Toyota Celica GT

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Detroit
I removed mine and the CEL came on but there havent been any noticable changes since it lit up. the increase is nice, I would rec. doing it. thumbsup

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Steven
ECelica Staff
Steven Dec 25, 7:32am - #72385 
2001 Spectra Blue Mica Toyota Celica GTS
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2001 Toyota Celica GTS

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Riverside, CA
highly unlikely

Originally Posted by shabu
You would see a performance gain only IF the ecu doesn't try to tune the engine to run cleaner (probably leaner) because it has no cat!
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slidr
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slidr Dec 25, 7:55am - #72386 

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2000 Toyota Celica

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Saint Louis, MO
Originally Posted by Steven
highly unlikely

Originally Posted by shabu
You would see a performance gain only IF the ecu doesn't try to tune the engine to run cleaner (probably leaner) because it has no cat!
I agree. Shouldn't hurt your car at all. I wouldn't do it because I couldn't stand to see that cel on all the time. And I forget who said this before but yeah, if the cel light is already on and another problem arises, you wouldn't know about it. I say do it at your own risk.

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VVTi03
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VVTi03 Dec 25, 9:20am - #72387 

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2003 Toyota Celica GT

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Gainesville/Ft.Lauderdale, FL
wont the crap comin outta the exhaust turn ur bumper all black and nasty?

2003 Celica GT 5spd
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JDMCelicaGTS
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JDMCelicaGTS Dec 25, 12:31pm - #72388 
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1985 Toyota Corolla GT

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Posts: 182
SGV*S.Ca
Originally Posted by VVTi03
wont the crap comin outta the exhaust turn ur bumper all black and nasty?

well.. i was planning on putting my stock exhaust but with a long tip a little that would stick out further than stock.. because when i had my N1 exhasut on, the tip came out further so it wont burn the bumper. I jsut want to try to get the most out of my stock muffler.

2000 GT-S - SOLD, 12/2003
1986 AE86 GT-S - STOLEN, unrecovered, 2/2004
1985 AE86 GT-S - built 4AGTE, SOLD 10/2009
2004 Camry LE, SOLD, 5/2007-10/2007
1994 GS300, 2JZGTE, HKS T04Z, 10/07-Current
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Speed4TheNeed
Caleb
Speed4TheNeed Dec 25, 2:08pm - #72389 

Caleb
2000 Toyota Celica

Joined: Aug 2003
Posts: 6,372
New Orleans, LA
Originally Posted by JDMCelicaGTS
Originally Posted by VVTi03
wont the crap comin outta the exhaust turn ur bumper all black and nasty?

well.. i was planning on putting my stock exhaust but with a long tip a little that would stick out further than stock.. because when i had my N1 exhasut on, the tip came out further so it wont burn the bumper. I jsut want to try to get the most out of my stock muffler.


that should work, then. just hope the cel doesnt come on thumbsup
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Steven
ECelica Staff
Steven Dec 25, 10:22pm - #72390 
2001 Spectra Blue Mica Toyota Celica GTS
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2001 Toyota Celica GTS

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Riverside, CA
the Check engine light will come on if you remove your cat off.
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NorwayGT
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NorwayGT Dec 25, 10:27pm - #72391 

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2004 Dodge SRT4

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Seattle, WA
y dont you just buy a racing cat?

was....5speed with i/h/e
15.41 @ 89.30mph 2.282 60'

is....04 srt4 stock
13.936 100.15mph 2.177 60'
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hybridcelica
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hybridcelica Dec 25, 10:31pm - #72392 
2000 silver/blue Toyota Celica
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2000 Toyota Celica

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Posts: 242
virgin islands
the cel "IS" going to come on!the best thing to do is dont replace the fat pipe that go didrectly on the header(the one with the divider)start your custom pipe after this pipe(you can both flange the stock cat and your test pipe so you can switch back later for emisions) and put back the two o2 sensors.you can do a search and find out about the device that mimics a perfect o2 sensor for obd2 systems. or check splitsecond.com.about the gains,awsome!all rpm band but esp above 6k,(upwards of 15 hp with a straight through canister at the back)loud though! you ever bolt your stock muffler off?its louder than that but heavy loud and if your bends are good with one long length of pipe with no welds it should be free of most of that ringing sound.
ps: since you would be having the exhaust down it will be a good idea to wrap your exhaust with 2"x1/8th thick exhaust wrap.helps with scavenging and reduce the the sound of pipe vibrations.takes some pics and let us know what your butt dyno feels(if you cant get it dynoed)

HYBRID:resulting from the combination of two or more mechanically dissimilar origins!
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shabu
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shabu Dec 26, 3:27am - #72393 
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I guess "tune the engine to run cleaner" was the wrong way to put it but I thought the ecu would go into "limp home" mode if it didn't see any difference in O2 one and O2 two. I don't remember where I read that and I haven't actually done it, so you just might prove me wrong. In fact me and a lot of other people would be happy if you did! Post your results if you do it!
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Speed4TheNeed
Caleb
Speed4TheNeed Dec 26, 5:50am - #72394 

Caleb
2000 Toyota Celica

Joined: Aug 2003
Posts: 6,372
New Orleans, LA
it shouldnt make your car "limp home". as as already noted earlier by someone else...your ecu will turn out, and this is ordinarily fine but you won't know if there is another problem should one arise.
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Spread Eagle
Senior Member
Spread Eagle Dec 26, 6:13pm - #72395 

Senior Member

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Posts: 610
South Sweden
Originally Posted by RoMkApOmKa
i Heard that you will gain some Hp if you take it off...But it's just what i heard... wink


Yepp...The gain shoud be 5-10 hp. But please, leave it on. There is allready enoug pollution.


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