All modern exhaust pipes have been designed to be rust resistant. But this only slow down the inevitable. The best way to keep your exhaust pipe rust-free is to take preemptive measures to stop it from building up in the first place.

Majority of people thought stainless steel will not rust or corrode which is not true. Due to stainless steel are used in home appliances and never exposed to outdoor condition or salt exposure during winter road condition specially up north.

If you take a stainless steel sink and let it exposure to same salt road conditions without washing and polishing it off it will start to rust on surface no matter what grade of stainless steel even T304 grade.

Just make sure to clean and wash the exhaust piping and use stainless steel polishing paste or cream it will bring back the stainless steel shine.

Here are a example video from youtube.com

https://www.youtube.com/watch?v=he56sB3nKzw

https://www.youtube.com/watch?v=Kn0bv5Qn4P4

https://www.youtube.com/watch?v=Z0q92ItcZjs&t=10s


Here is another video on how to clean up the stainless steel exhaust.


https://www.youtube.com/watch?v=rBMAnWDdrRU


Hope these video's helped out, Thank you !