Question for the Auto Mechanics, Rotten Egg Smell *REVISITED* Pg 5

How bout quit beating the shit of your car.

I am giving my honest experience as a 20+ year mechanic. Typically, the only times I smell what you are describing is when I drive a car hard that has not been driven hard. I can test drive cars the same way every time but some will smell sulphury and some not. Same models, same manufacturers.

I think it's more the catalyst needs cleaned out and I am heating it up more than the customer would during their routine driving. Does this sound possible under your circumstances?

Good answer!! Now that you mention it, yes. Like I stated in another post, this engine is supercharged and may be part of the reason.

Like you mentioned needing to be opened up a little more. Just put-putting around town seems to be when it is the worst. I have noticed that if I get out on the highway and open it up to 70+ mph for 40 or so miles, it seems to make a difference with the smell.

I am not a mechanic but I have had this problem before....

Your catalytic converter is prob going bad

I second that!

Is My Catalytic Converter Bad?

Rotten Egg Smell. If you're regularly getting wafts of rotten egg smell in and around your car.

[link to autorepair.about.com]



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Since you have given the most logical answer, I will reveal the vehicle specifics. Its a '01 Grand Prix GTP, not stock.

-I have replaced the supercharger pulley with a smaller one.
-Took the breather off and replaced with a K&N air filter that is not enclosed it gets all the air it wants.
-Performance wires
-Performance exhaust, cat back.
-Computer has been adjusted for the mods.

I cant remember for sure, but as I recall I did not have this problem until after I made the mods.

I tend to baby it around town. Except when some millennial pulls up next to me in their piece of shit rice burner thinking they are tough shit. They typically do not have anything for me, except when I break an axle in the process.

My 05 wrx sti will eat your car up mister, stock and all.

I am fairly mechanically inclined, I do all the maintenance and repairs on my cars. I have encountered an issue that has perplexed me and was looking for more insight.

I am getting a rotten egg smell. As I have always understood it, the rotten egg smell is the result of the sulfur in the fuel contacting the platinum in the catalytic converter.

I am going to withhold a few vehicle specifics, for now, because I have been getting some automatic generic responses that the catalytic is bad and needs to be replaced. I do not buy that, however, if this continues I believe on a long enough time line it will eventually ruin the catalytic. In this case if I were to replace the catalytic, I do not feel the problem would be resolved and would still continue.

I will say that if I change who I buy the fuel from it seems to stop temporarily. It seems to resolve it for 3-4 tanks of gas then it returns. I have three different places that I cycle through buying gas from.

What could be some other things that could cause this to happen? I will say that I am forced to use premium fuel.

Sorry for the lack of vehicle information and vagueness, this is just how my bullshit detectors work.

head gasket starting or already went

It is the cat converter, but the reason for the improper action by the cat converter is the wrong spark plugs. Those multi-ground electrode plugs look cool but the spark CURRENT (the heat producer) is divided among the arcs. Simple Ohm's law stuff. The spark is not hot enough. Make sure you use the exact MFR recommended spark plug. Not sexy just right.

P0420 code?

I am giving my honest experience as a 20+ year mechanic. Typically, the only times I smell what you are describing is when I drive a car hard that has not been driven hard. I can test drive cars the same way every time but some will smell sulphury and some not. Same models, same manufacturers.

I think it's more the catalyst needs cleaned out and I am heating it up more than the customer would during their routine driving. Does this sound possible under your circumstances?

You're not a very good mechanic...

Battery is fine.

No codes.

And your qualifications are what?

Actually, what he said and the way I normally drive the car has some relevance.

Hmm.. If it was me I'd clean the throttle body and the Mass air flow sensor. Then I'd go to the nearest raceway/dragstrip/small airport and get a few or more gallons of 110 octane and drive her hard a few times after she warmed up. That should clean her up quite a bit.

My old lady drives so tame in her Jag that I have to give her car some race gas and drive it aggressively every few months to keep it running in tip top.

Are you assuming what type of plugs I have installed?

I am fairly mechanically inclined, I do all the maintenance and repairs on my cars. I have encountered an issue that has perplexed me and was looking for more insight.

I am getting a rotten egg smell. As I have always understood it, the rotten egg smell is the result of the sulfur in the fuel contacting the platinum in the catalytic converter.

I am going to withhold a few vehicle specifics, for now, because I have been getting some automatic generic responses that the catalytic is bad and needs to be replaced. I do not buy that, however, if this continues I believe on a long enough time line it will eventually ruin the catalytic. In this case if I were to replace the catalytic, I do not feel the problem would be resolved and would still continue.

I will say that if I change who I buy the fuel from it seems to stop temporarily. It seems to resolve it for 3-4 tanks of gas then it returns. I have three different places that I cycle through buying gas from.

What could be some other things that could cause this to happen? I will say that I am forced to use premium fuel.

Sorry for the lack of vehicle information and vagueness, this is just how my bullshit detectors work.