then that would the be the blend door under the passenger side glove box behind the kickpanel, luckily this is the easiest one to replace.
you need a 7MM deep socket and 5.5mm socket
not sure of the part number, if you remove the kickpanel you can see the part number label on the actuator. your replacement actuator has to match that part number or it wont work even if it has the same number of pins. most autoparts stores carry the dorman you just need to be sure the dorman part crosses over to your actuator part number.
for this fix the dorman one should be fine. the dorman one is probably around $60, oe is going to be more and would likely need to be ordered or the dealer may have it.