Can I block this opening

[redmechanic]

Under the right hand passenger seat is a vent like flapper. Is this where the outside air comes in? I would like to block this off due to letting alot of engine noise in but I suppose it has a function. Just not sure what.Anyone ever notice this. Its on a 2025 crew

 

[Spike]

Under the right hand passenger seat is a vent like flapper. Is this where the outside air comes in? I would like to block this off due to letting alot of engine noise in but I suppose it has a function. Just not sure what.Anyone ever notice this. Its on a 2025 crew

That is the cab vent to let pressure out of the cab. You will hear it when you slam the door. The cabs are sealed up OK but not perfect. I have seen several people seal it up and didn't complain afterwards.
I have seen in other vehicles that not having enough of a vent will reduce the amount of air coming from the HVAC system due to trying to pressurize the cab.
It is fairly easy to remove the cover and you can tape the flap shut and see what you think. If you don't have problems you are good to go. If you have issues you can remove the tape