Does my car have an Air Cabin Filter?

You are correct that a 2000 Honda does not have a filter but the 2001 did so if this was a late build vehicle then you may want to check as they sometimes make changes before the actual module year change.

Here is a guide that helps with this:

https://www.2carpros.com/articles/how-to-change-an-air-cabin-filter

Here is a video that will give step by step instructions on a 2001 Civic:

https://youtu.be/gNPWN3hbkg0

However, even if your vehicle does not come with one, I attached the info from the manual that talks about how to treat this smell.

Please run through this info and let us know what you find.

Thanks