Hi guys,
We bought a Kia Sportage last month. My brother hook up the diagnostic checker on it and said something about the O2 Sensor. Dealer replaced the O2 sensor and assured us that it would take care of any problem. Later on, my battery started dying in the most random times and places and it wouldn't shift back into first gear at the drive-thru window. It took a few minutes to get the stick back up into first gear. Dealer told me to bring it back and he'd replace the O2 sensor again. We have no other means of transportation if this one goes.
Do I have any options as far as getting the dealer to repair the car, or possibly switch it for something else he has on the lot?
Thanks in advance for your time.

Make sure he replaced the O2 sensor used a new part from the dealership, and not a used part from another Kia. Since' the car is no longer covered by the Federal Emissions warranty act. So you may have to rely on any contract you may have signed with car dealer.