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I own a Mazda6 with V6 and auto transmission. So far 3000Km and only one problem,

Very strong sulfur smell from exhaust (rotten eggs...). Anyone else experience similar issue? Car is driven in Montreal, Quebec. Have tried different gasoline companies and always similar result.


NB: I am taking it to the dealer to have it checked. Hope its fixable...and not just bad gasoline in Montreal.


Thanks for help or comments.


Hi all,
I went to my Mazda dealer and showed them the problem. The car had been driven for 1 hour and they acknowledged the bad smell was surprising for this engine at normal running temperature.

They called Mazda for tech help and were told to call me to bring the car in for a check up on their computer. Apparently, there is some tweaking they can do to see if that fixes it (it may be running slightly rich which means less than optimum fuel economy).

Otherwise, its the catalyst.


More next week!
 

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Reading Topic: Exhaust problem

Hey i have the same problem with the smell from the exhaust. I at least smell 2 it times when i drive but let us know if it is a problem when you get it checked
Peace
 

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Replying to Topic 'Exhaust problem'

yeah i've noticed it too, but i've only got 300 miles on mine, so i haven't worried about it, but do please let us know what they say when you get it checked out
 

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Reading Topic: Exhaust problem

Rotten egg smell OUTSIDE of the car is usually the signs of a bad or clogged up catalytic converter. For us here in South Carolina, this is no major problem, just take the cat off the car and run straight pipe to the mufflers, no emissions testing here anymore. For states with testing, you might want to consider either just outrightly replacing the cats or taking it off the vehicle and knocking the guts out of it and just putting the shell back in place, so it looks legal. May not pass a sniffer test though.

Sulfer smell INSIDE the car is 100% normal though. Most new cars use a bunch of adhesives and stuff like that and as they break down, which is still normal, it gives off that same odor.
 

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Replying to Topic 'Exhaust problem'

I have this problem too. But it's slowly disappearing now. i'm at around 2000km but when it was still about 500km the smell was really strong
 

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Reading Topic: Exhaust problem

Same here, by 4000 miles the oder had gone. I thought it might have had something to do with winter blend gas.
 

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Replying to Topic 'Exhaust problem'

Here are some quotes I picked from a contour forum
(Remember that these cars are running a Duratec for a while...)

"If you get unburnt fuel that makes it to the cat it will smell like sulfer or rotten eggs."

"Rotten eggs is usually the smell of the cats not working right."

"Try changing gas stations. Worked for me when I had the problem."

"As others have said it could be gas related.
It could also be caused by an O2 sensor that's going bad resulting in the car running overly rich. Mine's been making that smell ever since I got it 2 years ago and it's just now that I've gotten the CEL for the bad O2 sensor. "

If everybody says the same, there must be something true in there...
 

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Reading Topic: Exhaust problem

From my experience in the Contour, it happens after a hard run and an extremely rich condition. I've got an OBD-2 connector for my laptop and I can watch and datalog fuel injector and o2 data. Whenever the o2's are extremely rich, without a doubt you can go behind the car and smell the sulfur. From everybody I've ever talked to, this smell is completely normal in the event of an extremely rich running situation.

"During oxidation catalyst operation, small amounts of sulfur in the gasoline combine with oxygen in the air to form oxides of sulfur (SOx). Sulfur dioxide (SO2) gas is also formed during oxidation converter operation. This SO2 gas is the same gas produced by rotting eggs. Although this gas has an unpleasant smell, it is not considered a major pollutant at present. "
 

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Reading Topic: Exhaust problem

Felt it once. I heard it was something about the AC.... The time I felt it was the first time we used it after the winter. Never felt it since
 

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Have 3200 miles on my 6s automatic. I reported the strong sulfur smell to local dealer and the response was for me to change brand of gas. In todays economy, everytime I buy gas it is from a different dealer (I shop for price)! Anyway, from one dealer to the next nothing changed. I tried a tank of premium and still no change.
 
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Replying to Topic 'Exhaust problem'

My Mazda dealer hooked up their diagnostic computer, got some data and sent it to Mazda for review. They have not gotten back to me with any news yet.

I have also tried different gas stations and no difference. The car has 4200 km now and it still has that strong odor in the exhaust.
 

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Reading Topic: Exhaust problem

I'd assume that the cats are probably not able to handle the richer mixture that the modified intake is giving...perhaps leaning out the mixture a bit will stop the smell

K
Savannah, GA
 

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Reading Topic: Exhaust problem

I just made a topic on this, I didn't notice this one.

I have the same issue but not all the time. It seems more evident on humid nights. ::shrugs:: Maybe its just a coincidence, I will pay closer attention to it.

With Ohio having some of the most strict emission laws in the country, I was getting worried but since its not considered a major pollutant, I feel a bit better... I just hate the smell.
 

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Replying to Topic 'Exhaust problem'

QUOTE
Originally posted by MyShadow


            I'd assume that the cats are probably not able to handle the richer mixture that the modified intake is giving...perhaps leaning out the mixture a bit will stop the smell

K
Savannah, GA[/b]
Now how is adding airflow with a modified intake going to make it richer? :wtf
 

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Reading Topic: Replying to Topic 'Exhaust problem'

Oh, sorry...more air flow lowers the temperature of the air that the intake thermostat registers. That's hooked up to the computer, which modifies the air to fuel ratio accordingly.
 

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Reading Topic: Exhaust problem

I've had this problem since day one with my 6. Dealer says it's a result of "Mazda engineering" common to many of their engines. He says it's unfixable.

yet another reason why I'mdoing the lemon law.
 
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