some wrong info in here, some right info in here.

their ARE TWO cats in the tC's exhaust system. The first is in the stock exhaust manifold (header) and is located as the collector (where all the tubes from the cylinders meet into one tube). The second Cat is located at the beginning of the mid-pipe, and after that is the resonator (like ack has pictured above).

All headers for any state are designed for OFF-ROAD USE ONLY, and no header is CARB exempt.

SO to answer your question, yes, an aftermarket header in CA would be illegal. I know CA is strict on alot of car related laws, so its your call if you wanna do it. But i would suggest to keep your stock exhaust manifold if you get cought, or if you have to take the aftermerket header off for inspection.

as for what the one user said about keeping the heat shield, you cant use it on an aftermarket header unless you wanna take your aftermarket header to a machine shop, and have them make brackets for you to be able to mount it to the aftermarket header, beacuse there are NO brackets on ANY aftermarket header for the tC.

 

haha devil, looks like we were posting at the same time... but you beat me. i had a longer detail post that held me up damnit! lol

 

the megan midpipe removes the 2nd cat and resonator, but puts its own resonator there. there are 2 cats on the tc. one on the header, and the 2nd on the mid pipe.

 

Well Im just glad that I was right that there are 2 cats, but I was just wrong in where one was lol I was thinking of replacing the header and S-pipe and leave the mid-pipe. At least I know now id have at least one cat! Thanks for the info even though im not the OP!

*edit* or on second thought I could replace the s-pipe and mid pipe and still look stock under the hood!

 

if you add an aftermarket header, you also MUST add an antifouler (aka spark plug adaptor) to the spipes bung for the o2 sensor. why? because your allowing more flow to go through your exhaust system, and the o2 sensor will detect that and through a CEL, because it thinks soemthing is wrong with the 1st CAT (which the sensor is right, it things the CAT is messed up because its reading more flow, and the CAT should restrict some of that flow... but since you removed it, there isnt much to resist flow). so you screw the antifouler into the spipe, and the o2 sensor into the antifouler. what this does is it moves the o2 sensor farther away from the spipe so that it isnt reading the direct flow through the spipe, it is only reading a limited amount, there for tricking it to believe the flow rate is correct.

 

Would I have to do that if I replace just the S-Pipe and Mid-Pipe?

 

nope. if u keep the factory exhaust manifold, you dont need the antifouler

 

Thank you for that info!

 

not a prob.

 

To the best of my knowledge, it is unlawful to remove a perfectly working cat no matter where you live, CA is just the only one that will check you for it. Unfortuately, there are no legal engine mods you can do here in the sunshine state(or is that florida? oh well) 'cept little things that will fly under the radar like plug wires, lightened pullets etc etc. If you are hell bent on a header, or any other ilegal mod, it would have to be removed come smog time. And all things considered, lets say you did a header+cai. In the time it takes to un-install all that, throw on an extra hour or so and you could've uninstalled a stage 0....

 

i said all of that above... besides the turbo / pulley mods cause he didnt ask about that...

 

Just drivin it home for him

 

haha, sounds better from a local. lol

 

Yeah, fig'd i'd throw out the turbo/pulleys idea too

 

Yeah, Florida is the sunshine state, although we get a lot more rain than sun.

And I've heard of S-Pipes alone causing CELs as well, and that the antifouler/O2 simulator tricks don't always work. That's part of the reason I never did it. But if I heard wrong, I might just buy an S-Pipe and a midpipe. :D

 

so your basically saying that there are 2 cats and the TC would maybe pass the test with only one? sounds like a header would be more of a pain then something good...what if i kept the stock header and just got a mid pipe?? would that effect anything? and would i get any gains from that...so all engine mods are illegal...so doesnt that mean that an CAI would be illegal also?

 

you can always put your stock header when it comes time for smog its not that big of a hassle....in what 4-5years?

 

groundforce...to sum up the info...
all aftermarket headers are illegal, they are for off-road use only for our car. It does delete the primary catalytic converter and you WILL be nailed come smog check time. It is all based on two things which you can go around...which are the CEL showing up due to it sending an incorrect mixture through the MAF i believe (correct me if i'm wrong which i might be) but it does cause a CEL...correctable by the antifouler method and also it will not pass the visual inspection done by any law enforcement official and by the smog check station/state referee. There is also a way around this which is something myself and Street Image in Baldwin Park, CA will be working on shortly and that is to make a custom mount and place the stock heat shield over the aftermarket header and cut a hole for the antifouler which will hopefully pass both visual and emissions still. We'll wait and see on that though. Anyhow, to answer ur other question, CAI is also illegal in cali as is any aftermarket intakes whether SRI or CAI due to no longer having the carbon filter in the intake. a mid pipe would be fine as it is after both of your cats but an s-pipe eliminates the second cat also making it illegal in cali...and yes, pretty much any engine mods are illegal if seen...a pulley is easy to get away with and spark plugs and wires are also easy to cover up...and the supercharger from TRD is also CARB legal...that's about it though. Hope this helps

 

buddha, the cel trips with a header for the reason i stated above. move exhaust flow, so it thinks the cat is bad (which its correct because its removed in the header). the 1st sensors in the header detects a/f ratio, and the 2nd o2 sensor detects flow.

intakes are for off road use only as buddha said

you could replace the mid pipe and get one with a hi flow cat and a resonator, but you wont see any gains with it (maybe 2whp)

and your correct, the anti-fouler doesnt always work for people. but i would say 85% of the time it does. its worked for me, i havent had one cell (knock on wood)

 

ok i am catching on now...wat about just an exhaust would that effect anything? cuz i just bought an Injen SES for my scion?