C0278 Scion - what is the repair of this problem entailing?

Question

My scion xD suddenly had this engine light turn on and this is the code I got. The dealer is making a big deal about scheduling and dropping off the car, I got the code run at Oreilly. Just so I am prepared, this is a brand new car and I don't want to have to pay for repairs at this point. The dealer should cover this under warranty and it is not a big deal, right????