Do NOT install factory cats
Car will sound like crap compared to now and you you tune it(trust me you will) you will have less power.
Call the dealership and tell them that you want to keep them on since you bought the car like that. If they say no tell them youll report them for selling a non emissions legal car, and a modified car(warranty).
Either that or when you go in say the owner sent you the cata but you never had time to put em in.