* Heat: The exhaust system is exposed to a lot of heat from the engine, which can cause the metal to oxidize and rust.
* Moisture: The exhaust system is also exposed to a lot of moisture, both from the inside and the outside. This can cause the metal to rust even faster.
* Chemicals: The exhaust system is exposed to a variety of chemicals, including gasoline, oil, and antifreeze. These chemicals can also cause the metal to rust.
* Salt: If you live in an area where roads are salted in the winter, the salt can also cause the exhaust system to rust.
All of these factors can contribute to the exhaust system being the first part of a car to rust.
