Question about catless header smell

[Mr.Impreza]

Hey guys, quick question. If I keep my stock front pipe, would the catless header still make a smell outside the car and inside the car?

[FRSBRZGT86FAN]

Originally Posted by Mr.Impreza

Hey guys, quick question. If I keep my stock front pipe, would the catless header still make a smell outside the car and inside the car?

Not as bad as with no cat, for the cold start while the secondary cat gets to temp you might get a whiff of it, also if you park in a garage you'll still smell it.

Not speaking from direct experience as I'm going to get a header this summer, but I know from a friend with BR-Z with borla UEL, and he agrees with me as well, it's very much apparent on cold starts and in enclosed areas with little wind. Also you should now the idle is surprisingly loud on cold starts because of the way modern cars high idle at start with the valve overlap and high idle to warm things up

[phrosty]

It's not horrible but the smell is definitely there.

[jawn]

Mostly on cold starts. Cats have to warm up.

[golfyankee2121]

Originally Posted by Mr.Impreza

Hey guys, quick question. If I keep my stock front pipe, would the catless header still make a smell outside the car and inside the car?

Originally Posted by FRSBRZGT86FAN

Not as bad as with no cat, for the cold start while the secondary cat gets to temp you might get a whiff of it, also if you park in a garage you'll still smell it.

Not speaking from direct experience as I'm going to get a header this summer, but I know from a friend with BR-Z with borla UEL, and he agrees with me as well, it's very much apparent on cold starts and in enclosed areas with little wind. Also you should now the idle is surprisingly loud on cold starts because of the way modern cars high idle at start with the valve overlap and high idle to warm things up

I would agree with what everyone else has said here. I have catless UEL with stock OP/FP, and I can only really smell fumes on cold starts, and under heavy acceleration. To @FRSBRZGT86FAN 's point about the loud cold starts, you can have it tuned out with OFT (and I'm sure EcuTek as well, but someone else will have to verify me on that) because the high RPM cold start is not necessary without a cat in the header. My cold starts usually hover around 1100-1200 RPM now, which is MUCH quieter than the 1800-1900 RPM cold starts.

-J.B.

[Mr.Impreza]

Yeah...I'm a bit sad guys about the smell....but see, my issue is that I don't want no gas smells, especially with a kid coming in the very near future and i drive this car on the weekends with my wife and it just don't be a pleasant environment.
I'm going to just go the catted way then....will just wait to find a catted header for sale.
Will go catted fp/op + catted header + tune.

I would love to go catless, cause there is more gains and it's sup much cheaper...but I don't want any gas smells.

[NyC Zn6]

no I only smell corn juice

[jawn]

Originally Posted by Mr.Impreza

Yeah...I'm a bit sad guys about the smell....but see, my issue is that I don't want no gas smells, especially with a kid coming in the very near future and i drive this car on the weekends with my wife and it just don't be a pleasant environment.
I'm going to just go the catted way then....will just wait to find a catted header for sale.
Will go catted fp/op + catted header + tune.

I would love to go catless, cause there is more gains and it's sup much cheaper...but I don't want any gas smells.

Well, I only smell it if I have the windows down immediately after starting the car, but it is what it is.

[jvincent]

I have the OFH (no cat) with the stock OP and have never smelled anything in my car.

My routine is as follows:

1. Open garage door.
2. Get in car.
3. Start car.
4. Reverse out of garage.
5.

Even when I am updating the tune and I let the car idle for over a minute after starting the car before I leave the garage I never smell anything in the car.

[jawn]

Originally Posted by jvincent

I have the OFH (no cat) with the stock OP and have never smelled anything in my car.

My routine is as follows:

1. Open garage door.
2. Get in car.
3. Start car.
4. Reverse out of garage.
5.

Even when I am updating the tune and I let the car idle for over a minute after starting the car before I leave the garage I never smell anything in the car.

I suppose that is a separate question, and one that may or may not be relevant to the OP - is there a smell, or is there a smell in your car? Barring an exhaust leak, you shouldn't smell it inside of your car.

[jvincent]

The OP was concerned about smells inside and outside of the car.

I guess if it were really bad you could smell it in the car, even without a leak, which is what I wanted to let him know about.

I assume that there will be a smell outside irrespective of catted header or not at startup so I don't see how that would play into the decision.

[jawn]

Originally Posted by jvincent

The OP was concerned about smells inside and outside of the car.

I guess if it were really bad you could smell it in the car, even without a leak, which is what I wanted to let him know about.

I assume that there will be a smell outside irrespective of catted header or not at startup so I don't see how that would play into the decision.

Yeah, I missed that the first time around. Derp.

[fumanchu1]

Originally Posted by Mr.Impreza

Yeah...I'm a bit sad guys about the smell....but see, my issue is that I don't want no gas smells, especially with a kid coming in the very near future and i drive this car on the weekends with my wife and it just don't be a pleasant environment.
I'm going to just go the catted way then....will just wait to find a catted header for sale.
Will go catted fp/op + catted header + tune.

I would love to go catless, cause there is more gains and it's sup much cheaper...but I don't want any gas smells.

Turn the car on, walk back inside to get the kid by the time you get back it has warmed up and there should not be any smell.

[bababooey]

FWIW recently installed catless w/ aftermark OP, stock front/mid pipe, stock muffler. I had not noticed any more fumes past startup revs.