# Why does my car smell like sulphur? **URL:** \ **Category:** Factual Questions\ **Created:** [February 16, 2007, 12:46am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428 "2007-02-16T00:46:56Z")\ **Posts on this page:** 15\ **Page:** 1
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [February 16, 2007, 12:46am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/1 "2007-02-16T00:46:56Z")
Sometimes, not always (hence “sometimes”), when I’ve been diving the 1995 Nissan Crashfinder I notice a sulphur smell coming off the car when I shut it off and walk away. I’m pretty much unwilling to believe it’s something coming up off the road because I’ve never noticed it on any other car. Only thing I can think is that there’s some sulphur in the fuel (probably not unusual, but I know zip about the chemical composition of gasoline) that’s not being burned right. My first instinc is to blame the catalytic converter because I’ve never trusted them since one broke into my house and stole all my mustard. But that’s another story. So…what’s up? ---
**Author:** ![SmartAleq](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/smartaleq/32/163_2.png) [@SmartAleq](https://boards.straightdope.com/u/SmartAleq)\ **Post date:** [February 16, 2007, 1:13am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/2 "2007-02-16T01:13:09Z")
Catalytic converter’s going out. Better get it looked at now or it could be more expensive down the road… ---
**Author:** ![boytyperanma](https://avatars.discourse-cdn.com/v4/letter/b/4491bb/32.png) [@boytyperanma](https://boards.straightdope.com/u/boytyperanma)\ **Post date:** [February 16, 2007, 1:19am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/3 "2007-02-16T01:19:40Z")
WAG your car is on it’s way to hell and getting real close thus the sulfur smell. ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [February 16, 2007, 1:27am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/4 "2007-02-16T01:27:24Z")
Oh it’s already _from_ hell. It’s big, green, filthy and ugly–the kids call it Shrek. OK, the Cat is hereby indicted as the source. But why? Is it hosed? Is the car not digesting gasoline properly like every other car I’ve had (ethanol intolerant?). The V-6 3.0 has plenty of power in the 0-30 mph range, but if you get it on the highway and run into hills you’re doing well if you can keep it at 55 in 4th gear. Also, it sucks on gas, probably 16 mpg. No check engine lights are coming on. Someone here at work just flipped out “Bad fuel injector.” anything to that? This person is usually a dumbass. ---
**Author:** ![badkittypriestess](https://avatars.discourse-cdn.com/v4/letter/b/8baadc/32.png) [@badkittypriestess](https://boards.straightdope.com/u/badkittypriestess)\ **Post date:** [February 16, 2007, 1:30am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/5 "2007-02-16T01:30:27Z")
Did you feed it rotten eggs?? 😃 ---
**Author:** ![Harmonious\_Discord](https://avatars.discourse-cdn.com/v4/letter/h/74df32/32.png) [@Harmonious\_Discord](https://boards.straightdope.com/u/Harmonious_Discord)\ **Post date:** [February 16, 2007, 2:15am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/6 "2007-02-16T02:15:36Z")
The catalytic convertor is likley the cause. [I have this link on some common reasons for failure.](http://www.bmwe34.net/E34main/Trouble/Catalyticconv.htm) Please note this on the page’s bottom. > [@](#): > > If a vehicle caused the OEM catalytic converter to fail, it could cause the NEW CONVERTER to fail as well. ---
**Author:** ![Quiddity\_Glomfuster](https://avatars.discourse-cdn.com/v4/letter/q/c4cdca/32.png) [@Quiddity\_Glomfuster](https://boards.straightdope.com/u/Quiddity_Glomfuster)\ **Post date:** [February 16, 2007, 2:46am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/7 "2007-02-16T02:46:51Z")
I think you need to watch what you eat and quit blaming the car. Points, however, for coming up with a whole new twist on ‘pull my finger’: ‘open the car door!’ 😃 ---
**Author:** ![Rick](https://avatars.discourse-cdn.com/v4/letter/r/9f8e36/32.png) [@Rick](https://boards.straightdope.com/u/Rick)\ **Post date:** [February 16, 2007, 5:06am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/8 "2007-02-16T05:06:50Z")
The sulpher smell is from sulpher in the fuel. The converter has nothing to do with this smell. Try a different brand or grade fuel. If that fixes the problem it is not the car, its the fuel. I have had sulpher smell on brand new cars, changing the fuel fixes the problem. ---
**Author:** ![A.R.Cane](https://avatars.discourse-cdn.com/v4/letter/a/ee7513/32.png) [@A.R.Cane](https://boards.straightdope.com/u/A.R.Cane)\ **Post date:** [February 16, 2007, 7:23am UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/9 "2007-02-16T07:23:29Z")
I thnk there are several possibilities. It could be the fuel you’re using, or it could be that the fuel/air ratio in your engine is too rich. Unburned fuel will cause the catalytic converter to overheat, producing the sulpher odor. This condition will also, dramatically, shorten the life of the converter, so it should be corrected asap. These are the two most likely causes. It could also be that the converter is failing. **Rick** is far more knowlegeable than I am, about auto mechanics, but I disagree w/ him on this one. ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [February 16, 2007, 7:08pm UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/10 "2007-02-16T19:08:36Z")
[QUOTE=Rick] The sulpher smell is from sulpher in the fuel. The converter has nothing to do with this smell. Try a different brand or grade fuel. If that fixes the problem it is not the car, its the fuel. I have had sulpher smell on brand new cars, changing the fuel fixes the problem. [/QUOTE] I can easily do some science here and pay attention to where the gasoline is coming from & what grade is used. Which should really be a lot of fun. Is the bad cat –\> sulphur connection a deeply-rooted myth then? And more to the point, if I pretend not to care about it, will it damage the car? ---
**Author:** ![VenusProbe](https://avatars.discourse-cdn.com/v4/letter/v/e495f1/32.png) [@VenusProbe](https://boards.straightdope.com/u/VenusProbe)\ **Post date:** [February 16, 2007, 8:21pm UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/11 "2007-02-16T20:21:51Z")
My car does that too, I found that if I use Shell gas it freakin stinks of sulpher a few minutes after I shut it off, the smell lasts for hours if the car is sitting. No Catalytic converter (67 Mustang) so I’m pretty sure it’s the gas. ---
**Author:** ![Belrix](https://avatars.discourse-cdn.com/v4/letter/b/ed655f/32.png) [@Belrix](https://boards.straightdope.com/u/Belrix)\ **Post date:** [February 16, 2007, 8:43pm UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/12 "2007-02-16T20:43:47Z")
Anecdotal but I was recently missing on one cylinder, a shorted spark plug wire, and pushing a lot of unburned fuel out the tailpipe. There was a strong smell of sulphur until I got it repaired. Does your engine feel like it’s missing on a cylinder? Shuddering? Rough idle? ---
**Author:** ![Belrix](https://avatars.discourse-cdn.com/v4/letter/b/ed655f/32.png) [@Belrix](https://boards.straightdope.com/u/Belrix)\ **Post date:** [February 16, 2007, 8:49pm UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/13 "2007-02-16T20:49:33Z")
That website for failed Cat converters is cool but doen’t tell you how to check it. Is there a good way that doesn’t require a cutting wheel? The joint in front of my Cat converter is loose, needs a gasket I guess, and it’s got a pretty good stream of exhaust that comes out - Implies that the catalytic converter is creating some sort of back-pressure - maybe normal amount. Plenty of white clouds behind the car on a cold morning, too. I passed my bi-annual emissions test this past summer. ---
**Author:** ![Inigo\_Montoya](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/inigo_montoya/32/124_2.png) [@Inigo\_Montoya](https://boards.straightdope.com/u/Inigo_Montoya)\ **Post date:** [February 16, 2007, 9:23pm UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/14 "2007-02-16T21:23:53Z")
[QUOTE=Belrix] Does your engine feel like it’s missing on a cylinder? Shuddering? Rough idle? [/QUOTE] Although I do not like the car, I have to admit that it runs as it should. ---
**Author:** ![VinylTurnip](https://avatars.discourse-cdn.com/v4/letter/v/b2d939/32.png) [@VinylTurnip](https://boards.straightdope.com/u/VinylTurnip)\ **Post date:** [February 16, 2007, 9:54pm UTC](https://boards.straightdope.com/t/why-does-my-car-smell-like-sulphur/392428/15 "2007-02-16T21:54:41Z")
[QUOTE=boytyperanma] WAG your car is on it’s way to hell and getting real close thus the sulfur smell. [/QUOTE] “Duuude! You’re goin’ to _Hell_!”