Multi Port Injection
 

What exactly is the multi-port injection box in the gen1 stratus with the 2.4L I4? I'm looking at a universal cold-air intake made by APC and I'm wondering what's inside it and what it does exactly does

generally speaking, a cold air intake is an extension of the air intake (bypassing the restrictive airbox (where your current air filter is), and pulling cooler air from the lower front of the car, instead of from the engine bay (like some cheaper short air intakes).
The multi-port injection refers to how the fuel and air mixture is injected to the cylinders. this all happens on the engine side of the throttle body.

If i had to guess, the multiport injection box you're looking at, is nothing more than your stock airbox, written as such to "show off" an internal feature of your engine.

thanks, man. I've been wondering what that is...I'm gonna wait till its a little warmer out then open that box up to see if I can just take it out