Previous Thread
Next Thread
New Reply
Print Thread
Rate Thread

Joined: Jul 2002
Posts: 181
Member
1985 Toyota Corolla GT
Member
1985 Toyota Corolla GT
Joined: Jul 2002
Posts: 181
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
1994 GS300, 2JZGTE, HKS T04Z, 10/07-Current

Joined: Sep 2003
Posts: 3,070
Specialist
2000 Toyota Celica
Specialist
2000 Toyota Celica
Joined: Sep 2003
Posts: 3,070
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.


Aqua Teen Hunger Force...number one in the hood, G

Joined: Jun 2003
Posts: 1,305
Specialist
2002 Toyota Celica GT
Specialist
2002 Toyota Celica GT
Joined: Jun 2003
Posts: 1,305
And it's illegal... To much kaka will spread out from your exhaust pipe. wave


Joined: Jul 2002
Posts: 181
Member
1985 Toyota Corolla GT
Member
1985 Toyota Corolla GT
Joined: Jul 2002
Posts: 181
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

Joined: Jun 2003
Posts: 1,305
Specialist
2002 Toyota Celica GT
Specialist
2002 Toyota Celica GT
Joined: Jun 2003
Posts: 1,305
i Heard that you will gain some Hp if you take it off...But it's just what i heard... wink

Last edited by RoMkApOmKa; Dec 22, 2003 9:43pm.

Joined: Sep 2003
Posts: 3,070
Specialist
2000 Toyota Celica
Specialist
2000 Toyota Celica
Joined: Sep 2003
Posts: 3,070
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

Joined: Aug 2003
Posts: 6,365
Likes: 1
Caleb
2000 Toyota Celica
Caleb
2000 Toyota Celica
Joined: Aug 2003
Posts: 6,365
Likes: 1
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.

Joined: Aug 2003
Posts: 6,365
Likes: 1
Caleb
2000 Toyota Celica
Caleb
2000 Toyota Celica
Joined: Aug 2003
Posts: 6,365
Likes: 1
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.

Joined: Jul 2002
Posts: 181
Member
1985 Toyota Corolla GT
Member
1985 Toyota Corolla GT
Joined: Jul 2002
Posts: 181
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

Joined: May 2003
Posts: 5,342
dikitzaps
1974 Toyota Celica
dikitzaps
1974 Toyota Celica
Joined: May 2003
Posts: 5,342
as long as you're o2 sensor stays in tact you should be fine.

Joined: Aug 2003
Posts: 6,365
Likes: 1
Caleb
2000 Toyota Celica
Caleb
2000 Toyota Celica
Joined: Aug 2003
Posts: 6,365
Likes: 1
i don't know if you cel will come on...but it shouldnt mess up your performance. should help it, actually.

Joined: May 2002
Posts: 3,286
ECelica Staff
2001 Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS
Joined: May 2002
Posts: 3,286
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?

Joined: Apr 2003
Posts: 2,442
Wheezy Joe
2002 Kawasaki Ninja 250
Wheezy Joe
2002 Kawasaki Ninja 250
Joined: Apr 2003
Posts: 2,442
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.

Joined: Oct 2003
Posts: 92
Member
Member
Joined: Oct 2003
Posts: 92
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!

Last edited by shabu; Dec 24, 2003 11:50pm.

Joined: Oct 2003
Posts: 1,547
Likes: 1
Pizza Geek
2002 Toyota Celica GT
Pizza Geek
2002 Toyota Celica GT
Joined: Oct 2003
Posts: 1,547
Likes: 1
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

Joined: May 2002
Posts: 3,286
ECelica Staff
2001 Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS
Joined: May 2002
Posts: 3,286
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!

Joined: Sep 2003
Posts: 3,070
Specialist
2000 Toyota Celica
Specialist
2000 Toyota Celica
Joined: Sep 2003
Posts: 3,070
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.


Aqua Teen Hunger Force...number one in the hood, G

Joined: Aug 2003
Posts: 79
Member
2003 Toyota Celica GT
Member
2003 Toyota Celica GT
Joined: Aug 2003
Posts: 79
wont the crap comin outta the exhaust turn ur bumper all black and nasty?


2003 Celica GT 5spd

Joined: Jul 2002
Posts: 181
Member
1985 Toyota Corolla GT
Member
1985 Toyota Corolla GT
Joined: Jul 2002
Posts: 181
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

Joined: Aug 2003
Posts: 6,365
Likes: 1
Caleb
2000 Toyota Celica
Caleb
2000 Toyota Celica
Joined: Aug 2003
Posts: 6,365
Likes: 1
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

Joined: May 2002
Posts: 3,286
ECelica Staff
2001 Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS
Joined: May 2002
Posts: 3,286
the Check engine light will come on if you remove your cat off.

Joined: Aug 2003
Posts: 2,269
Specialist
2004 Dodge SRT4
Specialist
2004 Dodge SRT4
Joined: Aug 2003
Posts: 2,269
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'

Joined: Nov 2003
Posts: 242
Likes: 1
Member
2000 Toyota Celica
Member
2000 Toyota Celica
Joined: Nov 2003
Posts: 242
Likes: 1
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!
"...... code":every man is a shadow,let him be treated as such,until proven otherwise by a show of character or code!

Joined: Oct 2003
Posts: 92
Member
Member
Joined: Oct 2003
Posts: 92
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!

Joined: Aug 2003
Posts: 6,365
Likes: 1
Caleb
2000 Toyota Celica
Caleb
2000 Toyota Celica
Joined: Aug 2003
Posts: 6,365
Likes: 1
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.

Joined: Oct 2002
Posts: 608
Senior Member
Senior Member
Joined: Oct 2002
Posts: 608
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.

Join the conversation - Register Now or Log In to add your comment


Link Copied to Clipboard
Member Spotlight
Aerowilson182
Aerowilson182
2001 Toyota Celica GT
Auburn, AL

Posts: 260
Joined: August 2004
Thank you.: Props to Zen Motorsports for an outstanding job on the Turbo fabrication, and Props to Hass Autoworks for hooking me up with so many sweet parts, You guys Rock!
Random: "To give anything less than your best is to sacrafice the gift" ~Prefontaine
Show All Member Profiles 
Recent Topics
Spyder Headlight LEDs
by Dxnxld - Mar 25, 2024 6:51am
Anyone ever hear this noise?
by CeliacCelica - Mar 21, 2024 10:51am
Clunking sound (not sure where from)
by Juliansky - Mar 20, 2024 3:01am
Does anybody know where i can find a S53 trans rebuild kit?
by MoreRamenNoodles - Mar 19, 2024 8:57pm
Urgent
by SoloXKay - Mar 19, 2024 11:58am
OEM speedometer on aftermarket ecu
by Penaman99 - Mar 5, 2024 11:23am
Brake master cylinder
by Nigel100 - Mar 5, 2024 2:45am
newly purchased 2000 GTS
by CantShift - Feb 27, 2024 9:06pm
Customize Your Toyota Celica Privacy Policy · About · Contact
Privacy Policy · About · Contact
CelicaHobby.com is an independent Toyota Celica enthusiast website. CelicaHobby.com is not sponsored by or affiliated with Toyota Motor Sales, USA, Inc. in any way. The Toyota and Celica names and logos are trademarks owned by Toyota Motor Sales, USA, Inc.
© CelicaHobby.com, 2001-2024
Powered by UBB.threads™ PHP Forum Software 8.0.0
(Preview build 20230331)