Code reader?

It should have also said what bank, 1 or 2, it's on. It means the O2 sensor downstream of the catalytic convertor is not working as it should. It could be an O2 sensor not working properly, coolant temperature sensor not working properly, or a damaged exhaust system (catalytic convertor, exhaust pipe) or retarded timing. I would clear the code first, disconnect the negative battery cable for a half hour, and see if the code comes back. If it does test the downstream O2 sensors for voltage. If it varies a lot, between 200 and 600 millivolts, you probably have a bad catalytic convertor. This may still be under warranty. Ford has to warranty the emissions system for 70,000 miles, I'm pretty sure.