Non cat exhaust CEL?

[CASTREX]

Question. Any one knows if the Yaris will throw a CEL if I take off the cat? If it does, is there a way to go around that CEL?

[Black Yaris]

wich cat and how many of them do you plan on removing?

[cdydjded]

Yes you will get a CEL
Yes you can fool the computer by installing an O2 simulator on the 1 of the oxygen sensors:smile:

[CASTREX]

Didn't know the yar came with more than one CAT.

What's an O2 simulator?? Where can I find one of those? Are expensive?

[largeorangefont]

There is probably one cat but 2 02 sensors. the front one is for triming the air\fuel. dont touch that one. You want to mess with the 02 after tha cat.

You can buy an electronic CEL fix and wire it in, or got to pepboys and buy a couple spark plug anti foulers. Screw it into the pipe and screw the 02 sensor into the anti fouler.

[Schwebel]

Make sure to drill a small hole into one of the sparkplug non-foulers, so that the sensor reads that it is getting some emissions. I wouldn't waste like $80 on a simulator. I've used the non-fouler method on several cars and have never thrown a code and plus it costs like $6.

[CASTREX]

Thanks for the tips! A $6 solution! can't get any better

[Black Yaris]

There are 2 pre-cats and a regular cat on our Yarii

[eco]

Yep,3 stage cat.confirmed,hey its even in the manual.I am also thinking of fooling the sensors aswell,I am waiting for some links.

[elsteverino889]

Yep,3 stage cat.confirmed,hey its even in the manual.I am also thinking of fooling the sensors aswell,I am waiting for some links.

eco is gay dont listen to him!

[Black Yaris]

eco is gay dont listen to him!

:laughabove: good one elsteverino:thumbup: , I am sure his sexual preferance and/or his happiness has nothing to do with his ability to confirm the Yaris has a 3 stage cat. If you were to choose to not listen to him, you would be ignoring correct information that you may want to use in the future.

[jouslee]

Yea, looking at the diagram it seems like the front two are pre-cats, I'm not quite sure what they do in the yaris but on the 86-91 Rx-7's (They also had a 3 stage cat system) they would act like combustion chambers to burn the excess hydrocarbons that were thrown out by the engine.

[largeorangefont]

Yea, looking at the diagram it seems like the front two are pre-cats, I'm not quite sure what they do in the yaris but on the 86-91 Rx-7's (They also had a 3 stage cat system) they would act like combustion chambers to burn the excess hydrocarbons that were thrown out by the engine.

The precats are for when the engine is cold.

[CASTREX]

The precats are for when the engine is cold.


What could be a down side of removing all 3 stages of the cat on a Yar??

What is going to happen when the engine is cold and there are no pre-cats?

Besides de CEL and of course the non-legal exhaust?

A loss of torque could be expected or something like that?

[largeorangefont]

What could be a down side of removing all 3 stages of the cat on a Yar??

What is going to happen when the engine is cold and there are no pre-cats?

Besides de CEL and of course the non-legal exhaust?

A loss of torque could be expected or something like that?

You'll gain a couple HP, some smell, and a CEL unless you use a CEL fix of some sort on the sensor.

[CASTREX]

Well.... looks like my cat is going down in a couple of weeks.:thumbup: