Rotten Egg Smell from Exhaust

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gunia

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I've been having a rotten egg smell coming from the exhaust. I think its the CAT. I used to use premium exxon gas and switched to premium shell gas. The smell good better for a while, but now its back. I don't always smell it, only after hard acceleration or aggressive downshifts. I have a cold air intake and aftermarket exhaust. The car is a 2002 Chevy Camaro Z28 5.7L manual. I don't drive the car often in the winter, but it gets used at least 2-3 days/week in the summer. I have a short commute ~10 miles (30 mins of local roads). I didn't have this problem when I used to have a 50 mile highway commute. It has about 43k miles on it. Could the cold air intake and exhaust cause the car to run rich? I did find a leak in the intake that I fixed recently.

A friend gave me a product made by Solder-It called "The Original Catalytic Converter Cleaner and Deodorizer". I'm suppose to put this in the gas and run it through the system. Has anyone used this product or something similar with any success?
 
Originally Posted By: Jason2007
Rotten Egg Smell is a sign of a bad/clogged catalytic converter.


+1
 
It might just be me, but it always seems like when I smell it on the freeway, a Chrysler product(usually a minivan) just accelerated to jump into the fast lane or something.

I jokingly refer to it as Chrysler stink, lol
 
Do you guys think that the cleaner I mentioned would work? I'm kind off nervous to put this stuff through the entire fuel system. Just trying to avoid a $400+ dollar bill for cats. I'd also like to find out how to keep this from repeating.
 
Not necessarily a bad converter.Rotten egg smell is from unburned fuel being burned in the cat itself.The fact you can smell it means the converter is working.
You need to find the cause of the rich mixture,leaking fuel injector,faulty pressure regulator,clogged air filter,faulty temp sensor etc before cat is really damaged if its not already.
Any Check engine light?
 
We have used that stuff at work, sometimes it works to get rid of cat codes. we will use a misting wedge and suck it into the intake, then put one in the tank. have had about a 50% success rate. Someone mentioned a clogged cat, however if you have a clogged cat you would have a power reduction. We used to have a 87 olds station wagon with the 4cyl, and everytime we worked it up this one hill it would smell. I think that smell is just the cat reacting under certian conditions to certian fuels. you say you don't smell it all the time I would question your fuel control and speed of your o2 sensors. just some food for thought
 
Arg. I've got a letter from GM stating the terms of an extended warranty on the cats on your Z, but I can't find it. I was able to just look it up on an LS1 site though, and a poster indicated it is good for 10 years or 120k miles.

I have a friend that had a cat problem on his Trans Am. It did set a code, and caused the car to run poorly. His dealer replaced it under extended warranty, but hosed him by charging for the "diagnosis" and resetting the code. Crooks.
 
Did anyone put an aftermarket tune into your PCM (either an actual tuner person, or a 'hand held', plug into the OBD port by yourself type tuner)??

Did you change the MAF sensor, add a MAF Translator, or install a ported throttle body?

Mine has NEVER made this smell, no matter which brand of premium I've used, whether it was pre-10% ethanol or not, and no matter how hard I ran the thing in any range of ambient temps.
 
I didn't know there's an extended warranty on the cats. I'll check on LS1tech or some other forums.

I have never performed an aftermarket tune or changed anything except the CAI and exhaust. I bought the car used from a dealer in 2004 with about 24k on it. Not sure if there was something done to it before I owned it.
 
The smell is caused from the converter being overloaded. It hasn't failed yet, but IT WILL.

Figure out why your engine is running rich. Probably lazy o2 sensors that aren't yet causing a CEL.

If it's just momentary, I'd call it normal decarbonizing.
 
If the cat were bad, would I smell the odor when warming up the car or when idling after warmed up?
 
Some cats smell worse than others.
Often start up is the worst, until things get hot.
When your tank is almost empty, try another tank of fuel from some other good supplier. you have nothing to lose by trying this.
 
Originally Posted By: mechtech2
Some cats smell worse than others.
Often start up is the worst, until things get hot.
When your tank is almost empty, try another tank of fuel from some other good supplier. you have nothing to lose by trying this.


+1

Also, YES, you may still qualify for new catcons under the extended emissions warranty program.

Is it an SLP CAI system?? (That's what I have.)
 
Originally Posted By: mechtech2
Some cats smell worse than others.
Often start up is the worst, until things get hot.
When your tank is almost empty, try another tank of fuel from some other good supplier. you have nothing to lose by trying this.


I don't smell it at start up. Actually I drove it today and it didn't smell all day, except after some hard acceleration and engine braking. I've tried Exxon, BP, and Shell. Shell is the best so far.


Originally Posted By: dailydriver


+1

Also, YES, you may still qualify for new catcons under the extended emissions warranty program.

Is it an SLP CAI system?? (That's what I have.)


I wonder if I would need to have a check engine light to qualify, because I don't. And yes, its an SLP CAI system. The loose fit I had was between the lid and the MAF housing. Also the lid wouldn't seat properly with the rubber filter seal that comes with the kit so I removed the seal. One of the clamps that held the lid down would come loose.
 
Originally Posted By: gunia
Originally Posted By: mechtech2
Some cats smell worse than others.
Often start up is the worst, until things get hot.
When your tank is almost empty, try another tank of fuel from some other good supplier. you have nothing to lose by trying this.


I don't smell it at start up. Actually I drove it today and it didn't smell all day, except after some hard acceleration and engine braking. I've tried Exxon, BP, and Shell. Shell is the best so far.


Originally Posted By: dailydriver


+1

Also, YES, you may still qualify for new catcons under the extended emissions warranty program.

Is it an SLP CAI system?? (That's what I have.)


I wonder if I would need to have a check engine light to qualify, because I don't. And yes, its an SLP CAI system. The loose fit I had was between the lid and the MAF housing. Also the lid wouldn't seat properly with the rubber filter seal that comes with the kit so I removed the seal. One of the clamps that held the lid down would come loose.


The PCM still might have stored a trouble code, even without a CEL.
The ONLY air filter I've ever seen that needed that foam gasket with an aftermarket lid is the K&N.
All of the rest, including the Amsoil EaA, and AFE I currently use are a very tight seal to the SLP lid.
 
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