My wife started the car and it idled rough and sounded like it was missing out.
-check engine light on
-engine electronic message
-runs rough until you get up to speed.

Guessing catalytic converter and/or O2 sensor? If not any ideas?

How hard is it to change 02 sensor and if I take it in to dealer about how much is it to change out catalytic converter out here in sunny Las Vegas, NV if that is problem?

Thanks,

Dean