I own an 89' IROC Convertible with a 305. When i start the car up in the mornings, there is a strong smell (with the expectant puff of smoke). I know that these cars have a cronic problem, in regards to a little oil leaking into the cumbustion chamber. But the smell from the exhuast is sulphuric, and almost choking. When the engine is hot, you really don't notice the smell, even with the top down. I've been told that it could be antifreeze leaking into the cumbustion chamber. What's the problem? And, would adding another catalytic help any?

 

What kind of gas are you using? Some gas has higher sulfur content than others, in California it isn't much of a problem because there is very strict regulation. Antifreeze doesn't really smell like sulfur, you will know when you have an coolant leak by the smell.. I don't really think it is a problem, but it could lead to a shorter cat life. I really wouldn't add another cat...
You should probably just switch brands of gas.

 

Thanks...I am also told that if I use a thicker oil, it will reduce the oil leaks from those crappy valve seals. I also think my Cat is due for replacement.

 

The sulfur smell is from the cat itself. Usually the smell is a pretty good indication that it needs a new one.

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