Noise Engine Compartment

I have a 2015 Tacoma 4 door with @5000 miles on it.
Receintly I noticed a noise coming from the engine compartment. The noise occurs when turning off the engine. With the hood open , the noise seems to come from the right rear of the compt. It sounds like it could come from the heater system. It sounds like a door is closing, Is there a vacume door in the heater system that closes when you turn the engine off. It lasts about 2 seconds.

 

Smog pump. Totally normal.

 

Is there a smog delete?

 

On my old Honda dirt bike , they had a California smog kit that just took up space and looked ugly. Deleting it was for aesthetics over anything if I remember correctly.

Just curious that's all.

 

Don't think it'd be worth it, really. Not sure if it exists - don't think anyone has put the time into it.

@ OP - like others said, totally normal. I also have a '15, and did this same search when I first got my truck. 100% alright. Weird noise, but no worries.