Help identify weird noise

Ok guys, my truck is making a weird noise in the mid to rear undercarriage area. Almost like something is decompressing, like air bags. I’ve only heard it twice but it’s strange cuz it does it when the truck has been in the garage for hours. The one time I heard it, I started the truck and it went away. I wish I could Get a video. Anyone have ideas of what it could be? Thx

 

That is the emissions or fuel self check.
Forgot the actual name.

It is normal.

 

Oh cool. Thank God

 

Mine makes a noise like this every time I turn the truck off. First day I had it I heard it and was like WTF. Everything I saw said it was the emissions air pump purging fuel vapor from the system.

 

Ya, I’m just surprised it happens hours after the engine has been off???

 

I heard that on mine and feared the fuel pump was still running.

 

The noise that you hear hours after the truck has been shut off is usually part of the evap system and I’ve seen multiple places where it’s common to hear.

 

EVAP system leak detection check

 

It must be a Toyota/Lexus thing. My 4Runner did it and my Lexus ans Tundra do it too. First time It freaked me out too - car had been parked in garage for hours and I could hear the system running.

I don’t ever recall my other vehicles doing it.

 

Hi, New to Tundras.com. I have a 2019. This evap system noise is quite annoying while camping. Kicks on in the middle of the night and wakes me up. Is there a fuse I can pull to keep this from going off?

 

Welcome from NY. It's best to let it do the check.