This became apparent after I did the Deckplate and put in the Amsoil filter.
It’s an "intake whistle" that happens when the engine is under load at 2-3k RPM.
With the deckplate in place it is less noticeable but still present.

With the deckplate off and paper filter its almost totally gone.

I knew there would be more intake noise after the deckplate but it seems like it’s the filter that makes the most difference.

My Runner has almost 115k so I'm thinking it may be a clogged Cat.

Any others have this noise? Or is it normal?

 

I don't have any noise from mine.

 

I have no noise with mine either..are you sure that it is seated right?

 

That was one of the first things I checked after making sure no vacuum lines got disconnected. The edges were pretty oiley and kept slipping out of the corners on the first install. I wiped them down and they stayed. Also I stuck my hand through the deckplate (airbox off) and felt around to make sure it was making a seal.

 

My rig makes that same whistle. It's a the turbo - didnt you know?

I wouldn't worry about it. Mine has done that for the past 10K miles (deckplate mod installed).

 

I guess that will be my excuse.
The pseudo turbo 4runner

 

Mine has also been doing that for the last 6 months or so.
At first I thought it was radio static and kept reaching for my radio that was turned off