Oh, those wonderful compounds of sulfur,like a spring day-in a swamp. That hydrogen sulfide (rotten egg) smell or burning hair or other is usually scents are caused by a rich mixture in the catalytic converter and are usually cured by changing the O2 sensor.
The O2 sensor is essentially a battery that generates a voltage (when operating above 600 F) equivelent to the amount of oxygen in the exhaust. This voltage is a reference for the computer to set the mixture. Unfortunetly the sensor will often drift and give false information to the computer which gives you a rich or lean mixture.
When lean the engine will stumble or possibly die, mine died at part throttle in long right turns, like freeway on ramps. No brakes, no steering and no go with a pack of cars accelerating behind me,thats fun. When rich the Cat burns the excess fuel and gives some kind of interesting smells from the sulfur thats left in all gas.
If you haven't changed it in a while, change the O2 sensor, in general do it before every smog check or every 50K Mi, it's $50 worth spending.
Hope this helps
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