Car question: Why does my exhaust smell like sulfur?

pX

Golden Member
Feb 3, 2000
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For the last couple monthes the exhaust from my car (a 97 mirage) has really reaked, like rotten eggs. It's kind of embarassing at times. Any idea what is causing it, or what can stop it?
 

Thanatopsis

Golden Member
Feb 7, 2000
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<< For the last couple monthes the exhaust from my car (a 97 mirage) has really reaked, like rotten eggs. It's kind of embarassing at times. Any idea what is causing it, or what can stop it? >>



Stop feeding it beans.
 

TRUMPHENT

Golden Member
Jan 20, 2001
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Are you sure it's the car?:D It sounds like emissions controls have left the building. Get the car hooked up to a computer and see what the codes are. The O2 sensor and or catalytic computer may be culprits.
 

atom

Diamond Member
Oct 18, 1999
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Get your cataytic converter checked. I am pretty sure thats the problem. It may need to be cleaned or replaced.
 

woodie1

Diamond Member
Mar 7, 2000
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Have you changed brands of gasoline? Some cars' exhaust can emit a funny odor with some brands of gas. Try changing where you fill up.
 

Jal

Senior member
Mar 22, 2000
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I had this problem before. Mechanic told me to avoid Esso/Exxon fuels as they were very high in sulfer compared to others.

O2 sensor and Cat convertor could be too.
 

pX

Golden Member
Feb 3, 2000
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have tried different gas places, and different grades of gas,,, still no change. replaced some little emissions thing a month or so ago, i have no clue what it was, it was only a little piece the size of a short screwdriver, or something.
anyway, cataytic converter, how much money are we talking?
 

Viperoni

Lifer
Jan 4, 2000
11,084
1
71


<< have tried different gas places, and different grades of gas,,, still no change. replaced some little emissions thing a month or so ago, i have no clue what it was, it was only a little piece the size of a short screwdriver, or something.
anyway, cataytic converter, how much money are we talking?
>>



Likely an oxygen sensor.
~$100 installed, depending on car.
 

Rage187

Lifer
Dec 30, 2000
14,276
4
81
Easy solution..

Go to a Jiffy lube and get a Fuel injection cleaning...


Run you about $70


It will clean it all out..


This is very important..

Get it done once a year..
 

Amused

Elite Member
Apr 14, 2001
55,843
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It's more than likely the catalytic converter.

Since you've tried different gas, we'll rule out bad gas with high sulfur.

This unpleasant phenomena doesn't happen very often anymore but when catalytic converters were first put on new cars, it was fairly common. The converters got hot enough and the fuel mixture in the engines was so "lean" (too small an amount of air) that the sulfur compounds in the gasoline were converted to sulfur dioxide which smells pretty bad. As auto and truck engine fuel management system became more high-tech and sophisticated, it happens less often.

If your mixture is good, it's the catalyitic converter.

CCs run about $600.

BTW, this CAN be normal in newer cars when your engine is cold, driven hard or climbing a hill.


I've never heard of a catalytic computer, LOL But maybe I need one with all the pollution on the net ;)
 

crab

Diamond Member
Jan 29, 2001
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Catalytic Convertor

Years ago our 79 Cougar had that problem.
 

pX

Golden Member
Feb 3, 2000
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is this something i can get out of a junked car perhaps? the car i have is a salvage rebuilt, and the guy i bought it from has i think 5 or 6 similar model mirages.

found some "performance catalytic converter" on carparts.com thatd fit it for 135$. thats not too bad, but a little more than i want to pay.
 

Amused

Elite Member
Apr 14, 2001
55,843
13,937
146


<< is this something i can get out of a junked car perhaps? the car i have is a salvage rebuilt, and the guy i bought it from has i think 5 or 6 similar model mirages. >>



Before you have it replaced, have the mixture checked. Like others said, the O2 sensor can be bad, giving you too lean a mixture.
 

ImTyping

Banned
Aug 6, 2001
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<< Before you have it replaced, have the mixture checked. Like others said, the O2 sensor can be bad, giving you too lean a mixture. >>


Actually, it is too RICH a mixture that does it. When the O2 sensor is not working correctly, the computer will have the motor run rich all the time (like it does when it is cold). This lowers your gas mileage and causes the odor (the cat releases sulfer smell when a rich mix hits it hot).

For all of you who had to have your cat replaced...all I can say is HAHAHAHHAHAAAAAAAAAAAAAAAAAAAAAA! Some mechanic went on a nice vacation...then probably put your cat in another car that had the same "problem." 600 bucks for a catalytic converter...and he threw in the 25 dollar 02 sensor for free.
 

DDad

Golden Member
Oct 9, 1999
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I've been a mechanic for over 20 years, and I've primarily dealt with exhaust systems. This is a very common problem- generally caused by running gas with high sulpher content. What happens, the sulpher will deposit on the catalytic converter. When the Cat get's hot enough, the sulpher starts to smolder- hence the smell.
Audi,Ford, and Dodge recommend trying adifferent brand of fuel- in particular to use gasohol (if available). They caution that it may take several weeks (minimum 3-4 tanks of fuel), but that the problem will eventually cease. As far as the mixture being out of whack, I doubt it- that is usually a different smell




 

mastertech01

Moderator Emeritus Elite Member
Nov 13, 1999
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Moral of the story: Take it in to a professional to have it diagnosed, lest you spend money needlessly. It could be one of numerous conditions causing this problem. Its always wise to spend a little on diagnostics and a correct repair than guessing large amounts of cash away. Most manufacturer service departments stand by thier diagnosis too...so if they guess wrong they eat the followup diagnosis and repair.