Check Engine light on @5.7k miles and engine stalling at 4,000 rpms?
 

I bought my 2013 Automatic Scion FR-S in September of 2013. I drive to and from work, and on the weekends. Mostly local roads with small amounts of time highway. When I was leaving work, I remote started the car and let it ran for 12 minutes before the engine cuts off. I let it sit for about 8 minutes before I entered my car to leave work. I noticed on the dash that the check engine light came on. As I left work, I noticed that the throttle response was weird. Engine wasn't reving as hard as it normally does when I press the gas to a certain point. Once I got onto the highway, I floored it and the engine stalled at 4000 rpm. I tried slowly pressing on the gas and building up the revs and as soon as it hits 4000 rpm, it stalled.

Anyone have any insight?

Take it to the dealer. That's pretty much all you can do. Your car is in what's known as "limp mode." Basically it will get you where you need to go, but just barely and it won't do it for long before something fails.

Get the code scanned so you can see what the ECU thinks is wrong.

Limping and stalling sounds like a camshaft problem. There's a TSB for that if you got that.