What Causes the Smell of Rotten Eggs in the Car?

[DelLucia]

The smell of rotten eggs in the car is mainly caused by hydrogen sulfide in the exhaust. It is normal for the car to have a slight smell of rotten eggs, as hydrogen sulfide is one of the main pollutants emitted by vehicles. The rotten egg smell in the exhaust often occurs when the car is cold or has just been started. During this time, the temperature of the catalytic converter is too low to function properly, resulting in higher emissions of hydrogen sulfide. The reasons for unpleasant odors in the car's air conditioning system are as follows: 1. Accumulation of dust in the indoor filter and copper fins: After prolonged use, dust can accumulate in the indoor filter and copper fins of the air conditioning system. When this dust reaches a certain level, it can produce an odor, which is then dispersed into the air when the air conditioning is turned on. 2. Moisture inside the indoor unit: After cooling or heating, the indoor unit of the air conditioning system often retains moisture. If the air conditioning is turned off immediately without a drying or anti-mold function, this moisture remains inside, leading to the growth of mold over time and the natural production of a musty smell.