Strange noise

Can anyone help me identify this sound coming from underneath my '17 Sport? It's coming from somewhere in the middle, under the bed or cab. It's sort of hard to tell... It stopped as soon as I put the key in the ignition. I didn't turn it on.

https://youtu.be/ftSuWuo7MU8

 

Normal can’t remember what it’s called .there was a post on here about that noise .

 

Sounds like loose exhaust parts. Possible a heat shield rattling somewhere?

Less likely, but it could also be a crack in the exhaust pipe somewhere where it's almost separated in two. Probably not going to happen on a truck this young though.

 

Key off evap test...

 

My bad, I thought the truck was running ... Yeah EVAP system like others said.

 

Cool- Thanks! Not sure why I have never heard that before but apparently it's normal. I appreciate the quick replies.

 

It happens about 6 hours after shutdown.
The first time I heard it I had to think for a min.
What surprised me was my new Corolla.
It was louder.