Previous Thread
Next Thread
New Reply
Print Thread
Joined: Dec 2002
Posts: 293
dondiemand
Member
dondiemand May 30, 9:02pm - #19379 

Member
2003 Toyota Celica

Joined: Dec 2002
Posts: 293
So Cal
removing the cat

im trying to search the forum about removing the cat but couldnt find one..anyway, has anyone tried this? did you notice any gain? im thinking about removing the resonator and the cat to squeeze out more juice..any opinions?

oops! my bad, this should be under the Custom Mods section, somebody kindly move it there..thanks a lot!
Joined: Oct 2002
Posts: 610
Spread Eagle
Senior Member
Spread Eagle May 30, 9:15pm - #19380 

Senior Member

Joined: Oct 2002
Posts: 610
South Sweden
Removing the cat will give you around 7-10 hp. Atleast that is what ppl say here.


Joined: Dec 2002
Posts: 293
dondiemand
Member
dondiemand May 30, 9:19pm - #19381 

Member
2003 Toyota Celica

Joined: Dec 2002
Posts: 293
So Cal
wow! eek really??!! the only down side is it's illegal here in so cal..that's why im kinda iffy about it
Joined: Oct 2002
Posts: 610
Spread Eagle
Senior Member
Spread Eagle May 30, 9:30pm - #19382 

Senior Member

Joined: Oct 2002
Posts: 610
South Sweden
LOL. Illegal here to. But since when do cops do look under your car. grin


Joined: May 2002
Posts: 3,295
Steven
ECelica Staff
Steven May 30, 9:34pm - #19383 
2001 Spectra Blue Mica Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS

Joined: May 2002
Posts: 3,295
Riverside, CA
it sounds like shi*. it is pretty loud and you will get a check engine light because of the O2 sensors (2).
Joined: Dec 2002
Posts: 293
dondiemand
Member
dondiemand May 30, 9:37pm - #19384 

Member
2003 Toyota Celica

Joined: Dec 2002
Posts: 293
So Cal
steven, have you tried this before? how about replacing it with a high flow cat? will it make any difference?..or maybe i should just take my resonator off, huh
Joined: May 2002
Posts: 3,295
Steven
ECelica Staff
Steven May 30, 9:42pm - #19385 
2001 Spectra Blue Mica Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS

Joined: May 2002
Posts: 3,295
Riverside, CA
cut the resonator off, weld pipe in place.

get high flow cat and weld it in place of the OEM cat.

with these 2 mods, you'll notice a considerable gain in performance.
Joined: Dec 2002
Posts: 293
dondiemand
Member
dondiemand May 30, 9:55pm - #19386 

Member
2003 Toyota Celica

Joined: Dec 2002
Posts: 293
So Cal
great! i'll take your word for it! thanks steven cheers
Joined: May 2002
Posts: 3,295
Steven
ECelica Staff
Steven May 30, 10:21pm - #19387 
2001 Spectra Blue Mica Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS

Joined: May 2002
Posts: 3,295
Riverside, CA
don't get a ticket and get caught with a cat-less exhaust by the CHP, there is a heafty fine for that.
Joined: Apr 2003
Posts: 4,658
Evan
Rebel
Evan May 30, 10:22pm - #19388 

Rebel
2003 Toyota Celica GT

Joined: Apr 2003
Posts: 4,658
Washington
Quote:
cut the resonator off, weld pipe in place.

get high flow cat and weld it in place of the OEM cat.

with these 2 mods, you'll notice a considerable gain in performance.


Wouldn't a cheaper (and just as effective) alternative be to just hollow out the oem cat, after welding pipe in place of the resonator? That way you don't have to buy a high flow cat. Anyone have thoughts on this?

[Linked Image]
Joined: Jan 2003
Posts: 2,161
Street Prototype
ECelica Staff
Street Prototype May 30, 11:41pm - #19389 

ECelica Staff
2002 Toyota Celica GT

Joined: Jan 2003
Posts: 2,161
Guam, U.S.A.
if you remove the cat plus the resonator and overall is a straight pipe, you will here the POPping noise and its very annoying, very loud as well but the gain is noticable BUT you might get pulled over for that...

removing the CAT and replacing it with a resonator is what i did on mine and it sounds sweet plus the gain...

i will take pictures of it very very soon, so standby thumbsup

by the way, trust me on this one, i experimented on my exhaust a lot before rice

[Linked Image]
Joined: Apr 2003
Posts: 4,658
Evan
Rebel
Evan May 30, 11:59pm - #19390 

Rebel
2003 Toyota Celica GT

Joined: Apr 2003
Posts: 4,658
Washington
Quote:

removing the CAT and replacing it with a resonator is what i did on mine and it sounds sweet plus the gain...


Interesting.. do you have emissions testing where you live? and if so, how are you going to pass? deal

[Linked Image]
Joined: Apr 2003
Posts: 896
element_celica
Senior Member
element_celica May 31, 1:41am - #19391 

Senior Member

Joined: Apr 2003
Posts: 896
Michigan
if you remove the cat, won't the check engine light come on because of the 02 sensors?
i really hate seeing those check engine lights.
will the light still come on if you take out the resonator and replace the stock cat with a high flow cat? i was just looking at my exhaust pipes today and wanted to put a straight pipe in, but my friend told me about the 02 sensors and check engine light, that makes me not want to replace the cat... but i need more info about high flow cats

rip celi...
95 240sx
Joined: May 2003
Posts: 65
tomsgts
Member
tomsgts May 31, 2:37am - #19392 
Member

Joined: May 2003
Posts: 65
indiana
you can replace the cat with straight pipe just put the o2 sensors in the pipe because they are a important part in how your engine runs and you need them
Joined: Mar 2003
Posts: 206
Bradcelica
Member
Bradcelica May 31, 5:15am - #19393 
Member

Joined: Mar 2003
Posts: 206
KC, MO
yes, i believe you can have the o2 sensors welded onto ur straight pipe(someone will correct me if i'm wrong cheers)... you can also get a universal high flow cat and have the sensors welded onto it grin thumbsup

here is random technology's web site, they have a universal high flow cat that will fit our celis
randomtechnology

01 gt-liquid silver
i come from the water
[Linked Image]
Joined: Jan 2003
Posts: 2,161
Street Prototype
ECelica Staff
Street Prototype May 31, 9:50am - #19394 

ECelica Staff
2002 Toyota Celica GT

Joined: Jan 2003
Posts: 2,161
Guam, U.S.A.
no engine check light, no emission testing here, and the 02 sensor is not connected to the catalytic converter, check under your car and see if theres an o2 sensor connected to the cat converter, the o2 sensor is located before the catalytic converter commin down from the headers, if you can see yours connected on the cat converter, hmmmm thats weird but mine is not there...

like i said, ill post pics very soon...

[Linked Image]
Joined: Apr 2003
Posts: 896
element_celica
Senior Member
element_celica Jun 1, 2:06am - #19395 

Senior Member

Joined: Apr 2003
Posts: 896
Michigan
cool..so if you put a straight pipe to replace the cat and the resonator, will there be that ricey pop sound coming from the exhaust? kuz i dont want that, and i want to take the cat out to free up the exhaust system.
hmmm whats a resonator for anyway? to quiet down the exhaust noise?

rip celi...
95 240sx
Joined: Jan 2003
Posts: 2,161
Street Prototype
ECelica Staff
Street Prototype Jun 1, 8:49am - #19396 

ECelica Staff
2002 Toyota Celica GT

Joined: Jan 2003
Posts: 2,161
Guam, U.S.A.
Quote:
cool..so if you put a straight pipe to replace the cat and the resonator, will there be that ricey pop sound coming from the exhaust? kuz i dont want that, and i want to take the cat out to free up the exhaust system.
hmmm whats a resonator for anyway? to quiet down the exhaust noise?


the resonator serves to quiet down the sound, but when you have straight pipe all the way, yes you will have the pop sound and its totally gay, i had a straight pipe before but now im using the resonator as a cat converter

[Linked Image]
Joined: Apr 2003
Posts: 896
element_celica
Senior Member
element_celica Jun 1, 3:22pm - #19397 

Senior Member

Joined: Apr 2003
Posts: 896
Michigan
Quote:
Quote:
cool..so if you put a straight pipe to replace the cat and the resonator, will there be that ricey pop sound coming from the exhaust? kuz i dont want that, and i want to take the cat out to free up the exhaust system.
hmmm whats a resonator for anyway? to quiet down the exhaust noise?


the resonator serves to quiet down the sound, but when you have straight pipe all the way, yes you will have the pop sound and its totally gay, i had a straight pipe before but now im using the resonator as a cat converter


so you took the cat converter out and replaced it with another resonator? and you left the stock resonator too?
i've heard of people hollowing out the cat convertor also... how's that done?

rip celi...
95 240sx
Joined: Jan 2003
Posts: 2,161
Street Prototype
ECelica Staff
Street Prototype Jun 1, 11:19pm - #19398 

ECelica Staff
2002 Toyota Celica GT

Joined: Jan 2003
Posts: 2,161
Guam, U.S.A.
Quote:
Quote:
Quote:
cool..so if you put a straight pipe to replace the cat and the resonator, will there be that ricey pop sound coming from the exhaust? kuz i dont want that, and i want to take the cat out to free up the exhaust system.
hmmm whats a resonator for anyway? to quiet down the exhaust noise?


the resonator serves to quiet down the sound, but when you have straight pipe all the way, yes you will have the pop sound and its totally gay, i had a straight pipe before but now im using the resonator as a cat converter


so you took the cat converter out and replaced it with another resonator? and you left the stock resonator too?
i've heard of people hollowing out the cat convertor also... how's that done?


this will explain everything thumbsup

Linked Image

[Linked Image]
Joined: May 2002
Posts: 3,295
Steven
ECelica Staff
Steven Jun 1, 11:34pm - #19399 
2001 Spectra Blue Mica Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS

Joined: May 2002
Posts: 3,295
Riverside, CA
JD - look at my edit of your photo... isn't that "sensor" the cat? Is your mid-pipe stock? On the mainland, we have an O2 sensor before the cat and one after the cat.

Linked Image

This is a picture of my mid-pipe... no resonator. O2 sensors not are on the other side of the piping...

Linked Image
Joined: Apr 2003
Posts: 896
element_celica
Senior Member
element_celica Jun 2, 2:50am - #19400 

Senior Member

Joined: Apr 2003
Posts: 896
Michigan
what happend when you took out that sensor? did your check engine light come on? did you just take it off, or you cut the wires ?

rip celi...
95 240sx
Joined: Mar 2003
Posts: 206
Bradcelica
Member
Bradcelica Jun 2, 3:02am - #19401 
Member

Joined: Mar 2003
Posts: 206
KC, MO
i'm going custom; i have an obx racing muffler (with removable silencer). i'm about to have the resonator ripped out and have a 2 1/4" mid pipe put in. is the stock cat really that restrictive?? i'm not gonna yank the cat due to emissions, but if the stock cat is real restrictive then i'm gonna buy a universal random technology cat.

01 gt-liquid silver
i come from the water
[Linked Image]
Joined: Sep 2002
Posts: 209
eNinja
Member
eNinja Jun 2, 5:25am - #19402 

Member
2002 Toyota Celica

Joined: Sep 2002
Posts: 209
san antonio, texas
i wish i saw this thread a while back. i guess its been a while since ive checked the site. anyways. i did this mod. i removed the cat and the res and straight piped it to my TRD exhaust. it sounded horrible. hes right about the popping sound. i hated it so much, i paid another 60 bucks to have it put back but the shop damaged my o2 sensors in the process. my car sounds fine again but it runs crappy and i get the check engine light all the time. ive been in the process of getting them to replace it for MONTHS now. i threatened to sue them but hopefully i wont have to (its my friends dads shop). ive also been asking people to get me a set of used o2 sensors. theyre 150 bucks a pop at the dealer. i want some off a used gts. anywho, good luck.
Joined: May 2002
Posts: 3,295
Steven
ECelica Staff
Steven Jun 2, 7:31am - #19403 
2001 Spectra Blue Mica Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS

Joined: May 2002
Posts: 3,295
Riverside, CA
i'm going to get a straight pipe made for me for track purposes only smile
Joined: Jan 2003
Posts: 2,161
Street Prototype
ECelica Staff
Street Prototype Jun 2, 11:07am - #19404 

ECelica Staff
2002 Toyota Celica GT

Joined: Jan 2003
Posts: 2,161
Guam, U.S.A.
Quote:
JD - look at my edit of your photo... isn't that "sensor" the cat? Is your mid-pipe stock? On the mainland, we have an O2 sensor before the cat and one after the cat.

Linked Image

This is a picture of my mid-pipe... no resonator. O2 sensors not are on the other side of the piping...

Linked Image


Sorry Steven but i have to correct you on this one, that is not the catalytic converter, look at the pic below...

Linked Image
Linked Image
Linked Image

Toyota Celica Catalytic Converter 1986-1989
Linked Image
Toyota Celica Catalytic Converter 1981-1983
Linked Image

the old celicas have the O2 seonsors on their cat converter, our cars O2 sensor is separate...

the illustration i have with the resonator replaced is the cat converter.

our cat converter is a bolt on type, the one your talkin about on my illustration you edited is not a bolt on type, thats why we have Universal High Flow Cat converter so we can replace it if we want too... cheers



[Linked Image]
Joined: Apr 2003
Posts: 112
Miicha
Member
Miicha Jun 2, 1:07pm - #19405 

Member
2002 Toyota Celica GT

Joined: Apr 2003
Posts: 112
GeRmAnY
Hey Street Prototype

Can you get a sound byte of what your exhaust sounds like now or do you know where I can find one? I want to straighten out my resonator pipe too, but i wanna hear what it sounds like B4 i do it. I would really appreciate it.
Joined: Jan 2003
Posts: 2,161
Street Prototype
ECelica Staff
Street Prototype Jun 2, 9:09pm - #19406 

ECelica Staff
2002 Toyota Celica GT

Joined: Jan 2003
Posts: 2,161
Guam, U.S.A.
sure buddy, heres the video clip of my exhaust thumbsup

Click Here

[Linked Image]
Joined: Apr 2003
Posts: 112
Miicha
Member
Miicha Jun 3, 2:37pm - #19407 

Member
2002 Toyota Celica GT

Joined: Apr 2003
Posts: 112
GeRmAnY
KOOL KOOL I WANT IT!!! I WANT IT!!! rofl goodjob goodjob grin
Joined: Nov 2002
Posts: 344
tWiSteD
Member
tWiSteD Jun 3, 2:54pm - #19408 

Member
2000 Toyota Celica

Joined: Nov 2002
Posts: 344
Marietta, GA
thats a very nice exhaust! thumbsup

however, for you people thinking about the straight pipe system, i have a friend that tried it on his teggy, and got caught like the first week when he wasn't even racing. 4,000 dollar fine. could've put in a supercharger for that! spineyes

Not just another girl's car...
Joined: Apr 2003
Posts: 112
Miicha
Member
Miicha Jun 3, 3:03pm - #19409 

Member
2002 Toyota Celica GT

Joined: Apr 2003
Posts: 112
GeRmAnY
That sucks...but in DC i have heard louder... and they do not get pulled over..
Joined: May 2002
Posts: 3,295
Steven
ECelica Staff
Steven Jun 3, 5:39pm - #19410 
2001 Spectra Blue Mica Toyota Celica GTS
ECelica Staff
2001 Toyota Celica GTS

Joined: May 2002
Posts: 3,295
Riverside, CA
yea CHP will not like you if you get caught cat-less
Join the conversation - Register now or Sign in to add your comment


Moderated by  isaac 

Customize Your Toyota CelicaPrivacy 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, 2001-2016