exhaust smell

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On some vehicles, a sulfur smell or 'rotten egg' odor may be noticed coming from the exhaust system. The odor is usually noticed after a cold start, fast idle, extended periods of idling and full throttle acceleration. Sulfur smell is not an indication of an engine concern and will not cause reduced  driveability or durability of the engine or any of its emission components.
The sulfur smell or 'rotten egg' odor is caused by high amounts of sulfur in the petrol being used in the vehicle. The reduction section in your catalytic converter, the part that changes NOx and some CO (carbon monoxide) back to N2 and CO2, also has the tendency to start absorbing SOx, or oxides of sulfur when its internal temperature drops below about 500°C.  As sulfur is a natural contaminate in most fuels which, when burned, are emitted as oxides of sulphur.

When the engine is required to put out more power and the catalytic converter heats up over 600°C, the catalytic converter starts releasing the SOx as H2S and SO3.  The SO3 has no odor but the H2S (Hydrogen Sulfide) gas does, which is what you smell.  That usually means the reduction section of your converter IS working, regenerating itself, and purging the accumulated sulphur.   
Sulfur is normally eliminated during the refining process, but there is still fuel containing high amounts of sulfur on the market. It will most likely emit sulfur smell from the exhaust system. When high sulfur fuel is burned, there is a chemical reaction in the catalytic converter causing the sulfur to oxidize.
As the vehicle is driven, the oxidizing reaction odor in the converter will decrease with mileage and age.

Replacing the catalytic converter will not eliminate sulfur smell and replacement will just extend the period of time needed for the converter to 'age' allowing it to reduce sulfur smell to an acceptable level.

there is few thing can be tried to reduce the smell
1.Switch to a different brand of fuel and drive the vehicle for at least 100 miles. Monitor the decrease or
increase in sulfur smell.
2.Do not add any type of 'fuel additive' as this could add sulfur to the fuel and cause/increase the odor.
3.Try to avoid extended periods of short trip driving or aggressive acceleration.
4.Request information from your local fuel dealers on the amounts of sulfur in their gasoline. Try to use fuel
containing the lowest amounts of sulfur.
5.Visit the fuel company websites to stay informed on any changes in fuel or environmental regulations

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