resonator, or what? Options

[94odiecelica]

im installing new headers, but under the factory manifold, below the heat shield, there is something. people have told me it could be a second cat which would mess up me puttin the headers on, ive heard its the resonator, ive heard flex pipe. its the thing between the downpipe and the gasket from the header. i was just wondering what exactly that part was.

[SAE-HI]

mines is a second cat. most likely it'll be the same for yours

[94odiecelica]

i forgot to mention its a 94 st. dont know if that would matter or not

[SAE-HI]

i forgot to mention its a 94 st. dont know if that would matter or not

yeah it should be a second cat cause mines is a 95 st

[d3ath2009]

its a second cat.. as long as the main cat (2nd in line, almost in the middle of the car) is working properly, you should be able to take out the 2nd one (1st in the exhaust line) with the manifold and downpipe to install a header and downpipe

[richee3]

The flex pipe is exactly what it sounds like- a flexible section of pipe, usually right behind the exhaust manifold. It looks like cross weaved pieces of wire. The resonator will be closer to the muffler.

[d3ath2009]

^two cat systems have a cat between the manifold and downpipe (as described by OP).. flex pipe is part of the downpipe, almost at the other end of it..

[Smaay]

headers? how many do you plan on installing?

[SupraKid]

headers? how many do you plan on installing?

Hes going to put them when the turbo goes on...lolololololol


But op just remove the cat, as long as you have your 2 O2 sensors and the car will run fine. But youll fail an emission test if you have one.

[richee3]

Edit: Andrew said pretty much exactly what I was going to say. You'll be fine with the header, as long as you don't have to pass emissions.

This post has been edited by richee3: Feb 15, 2012 - 5:19 PM

[94odiecelica]

do you guys know which states require an emissions test? or a way to find out without asking every place or asking one place if its a state law? i live in pa. and i even called a toyota dealership service center and they said it was the resonator. we thought it was a cat, but i think it is. and this is the url for what i bought. i dont know (like height) if i can fit the first in like cat back in between where the headers and downpipe bolt together, so help?
http://www.ebay.com/itm/110812171946?ssPag...984.m1497.l2649

[richee3]

Not a Celica's exhaust but it's a generic diagram. Notice that the resonator is found at the back of the car, nowhere near the exhaust manifold.



You should drive to that Toyota dealership and slap the idiot who told you that was a resonator as opposed to looking up the diagram. As for emissions testing, you can Google it but you would probably know by now if they test your car since you would have to take it in for testing.

[94odiecelica]

ok. and so an emissions test isnt included in an inspection? i just always thought that. and thats how it is for basically any car exhaust?

[richee3]

Emissions could very well be included in an inspection. It really just depends on your state or really even your region. For instance, where I'm from in Illinois never does a single inspection, emissions test, anything. However, in Chicago, they do certain inspections. Same state, different regulations. The diagram I posted isn't for every car, but it's a pretty good example of most exhaust setups.

[94odiecelica]

ok so my best bet would to go to local places and ask what the rule of thumb is? and will my car run any different if i take it out?

[richee3]

As stated before, it should run the same as long as both O2 sensors are still there and intact. As I recall, installing a header on the 7A has decent returns. I know some members with a 5S put their original intake manifold back on for emissions testing but the 7A requires a little custom exhaust work since the header is too short and won't reach the factory exhaust under the car.

[94odiecelica]

As stated before, it should run the same as long as both O2 sensors are still there and intact. As I recall, installing a header on the 7A has decent returns. I know some members with a 5S put their original intake manifold back on for emissions testing but the 7A requires a little custom exhaust work since the header is too short and won't reach the factory exhaust under the car.

sorry, but that confused me a little. so your saying i might need to mod the headers i bought to get them to fit? and will the first cat fit in with the new headers?

[richee3]

No, the cat will not fit with the header. After you install a header on a 7A, there will be a gap in the exhaust between the header and the Celica's exhaust. You can have a shop fabricate a piece that will fit between the header and the car's exhaust that will bolt up so you can put the stock manifold back in when/if you have to do an emissions test.

[d3ath2009]

ive got an ebay header on my 7a.. u will have to add a 2-3 inch piece between the end of the down pipe and the flange for the cat thats under the car...

[94odiecelica]

really? well thats not exactly what i wanted to hear lol. thanks though guys

[Galcobar]

That generic diagram isn't useful in telling you what's actually under your specific car -- you'll note for instance it lacks a flexpipe entirely.

Toyota does not, as a rule, put the resonator at the end of the exhaust run -- they prefer to put a muffler at the end. Keep in mind a resonator is not a muffler, despite many marketers and retailers applying the term resonator to round-body mufflers. What you'll normally see is manifold-catalytic converter-flex pipe-resonator-muffler. The primary cat is often attached directly to the manifold and acts as a collector pipe. For those systems with two catalytic converts, the sub-catalytic converter will be mounted between the flex pipe and the resonator, with the resonator moving back from the front exhaust pipe to the centre pipe. In systems with two cats and two mufflers, the resonator is usually omitted.

If you want to know whether emissions testing is required in your state or county, check their website. Or Google emissions testing in your area, and get this: http://www.dmv.org/pa-pennsylvania/smog-check.php

[d3ath2009]

^primary is NOT attached to manifold on these cars.. mine has always had one cat from the factory and its the one down under the car

[94odiecelica]

^primary is NOT attached to manifold on these cars.. mine has always had one cat from the factory and its the one down under the car

so would that mean if yours is a 94 st and mine is too miine will be the same, or will they make 94 st's- some with one cat,and some with two?

[mandrek]

from what i can tell the 94-95 ST had TWO cat's, primary in the manifold, and secondary is located down stream.. (non cali-spec[my original setup]), and the 96+ST had ONE cat, down stream of the manifold (under the car) (non-cali spec)


With the changes in 96 (OBDII) with sequential injection, and better emisions control. looks like that they did not need to have a primary cat in the manifold (again, not sure about the cali-spec).. at least that is from what i have been able to gather.