2020 TRD Pro hissing sound like leaking air from behind rear tire

I got home from work about 45 minutes ago and when I got out of my truck I heard a hissing sound that made me think my rear driver's side tire was going flat. Well it isn't, and the sound is coming from somewhere behind the wheel. It's been 45 minutes and it is still making that noise. Any ideas?

 

I’d keep looking.. hard to guess what you’re hearing. Easy to find with your ear and some effort.

 

Spare going flat with a slow leak or did you run over a snake maybe? Gas tank pressure. That seems odd its been lasting so long.

 

Mine does this to would like to know if it is normal. Does sound like a flat but has happened a few different times.
I have a 2017 off road.

 

Could be the evap system doing some type of self test

Your truck is brand new, probably nothing to worry about

 

that's your fuel pump working, absolutely normal.

 

Time to feel like a moron: the tire was going flat, it had a screw in it. I thought with the amount of noise it was making after an hour it would have started to look flat, but apparently not. And I could've sworn it sounded like it was coming from deeper in than the tire.

 

Smog pump isn’t immediate and doesn’t last 45 min.

 

Fuel pump runs for 45 min after shut down and sounds like an air leak?

 

Good job, Jeff... little mental glitch and you came clean on it! Nothing no one hasn't done before!
Cheers, Jeff