Catless fumes in cabin

[Zabotkaaa]

Hey everyone, just put in Catless long tube headers and the cabin reeks. Especially during cold starts, and when at a stand still. Any advice? Was looking at high-flow cats but a buddy said it doesn’t change much. Thanks!

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[robvas]

Is this a trick question?

 

[sk47]

Hello; Gona need more information. An assumption is the exhaust is complete and tight. That the exhaust exits out the back of the car as is the normal position.
I do not know exactly what is done when removing the cats (catalytic converters) in terms of the oxygen sensors & the programming associated with emissions. On some vehicles there are primary and secondary O2 sensors. One in front of the cats and the second after the cats. I have not done a coatless setup so have wondered how the programming is altered.

 

[robvas]

I do not know exactly what is done when removing the cats (catalytic converters) in terms of the oxygen sensors & the programming associated with emissions. On some vehicles there are primary and secondary O2 sensors. One in front of the cats and the second after the cats. I have not done a coatless setup so have wondered how the programming is altered.

Mustangs have widebands in front of the cats and narrow bands behind the cats, on both sides of the exhaust. Programming doesn't really change, but the rear O2's will see the cats are not there and throw an inefficiency code

Supposedly if you run e85 instead of gasoline it will smell like Acqua di gio

 

[Zabotkaaa]

Is this a trick question?

No, lol. Why?

 

[EFI]

It is what it is. You eliminated highly efficient cats from filtering out pollutants, which as we all know are significantly higher shorly after cold starts.

You can add some Kooks green cats to help, but it will still smell especially at startup.

 

[Zabotkaaa]

Mustangs have widebands in front of the cats and narrow bands behind the cats, on both sides of the exhaust. Programming doesn't really change, but the rear O2's will see the cats are not there and throw an inefficiency code

Supposedly if you run e85 instead of gasoline it will smell like Acqua di gio

I currently have catless headers, catless connections into an H pipe, into corsa axle back. Everything is tight and sealed.. only thing I can think of is either the high flow cats, or assure no leaks by welding the whole thing together but that’d suck because then the whole system won’t be able to be taken apart unless i grind the welds off lol.

 

[robvas]

If you farted would you be surprised that you can smell it?

 

[Zabotkaaa]

It is what it is. You eliminated highly efficient cats from filtering out pollutants, which as we all know are significantly higher shorly after cold starts.

You can add some Kooks green cats to help, but it will still smell especially at startup.

Understandable. Kinda did it to myself lol. I’m 19 and it’s my daily so the fumes get annoying but I’ll learn to deal with it; or get cats like you said.

 

[Zabotkaaa]

If you farted would you be surprised that you can smell it?

LMAO. Fair point.

 

[2015 Silver GT]

Understandable. Kinda did it to myself lol. I’m 19 and it’s my daily so the fumes get annoying but I’ll learn to deal with it; or get cats like you said.

Do you think breathing in the fumes are healthy? Did you not understand this was going to happen?

 

[junits15]

does it smell when you're driving? Or only at a standstill.

 

[Zabotkaaa]

Well, I wouldn’t necessarily say healthy but I did check a lot of forrums and they said it isn’t a huge health issue as long as I’m not directly inhaling the fumes. Its not terrible, but definitely noticeable. I understood it would happen but don’t believe how drastic it’d be.

 

[DougS550]

Hey everyone, just put in Catless long tube headers and the cabin reeks. Especially during cold starts, and when at a stand still. Any advice? Was looking at high-flow cats but a buddy said it doesn’t change much. Thanks!

Have you leak checked All clamps? I can see having some type of fumes with pump gas but I wouldn't think it would fume the cabin.
You could try this?

Do you think breathing in the fumes are healthy? Did you not understand this was going to happen?

Have you checked for leaks? fumes out the rear shouldnt fume up your cabin.

try this

 

[Zabotkaaa]

does it smell when you're driving? Or only at a standstill.

I’d like to say only when stand still/cold starts but it’s hard for me to be sure because once it’s in the car it lingers. But I do notice if I’m driving and roll the windows down for the fumes to exit the cabin it definitely is less noticeable.

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