p1128 sensor faled inspection 2000 Hyundai Accent

I have a 2000 Hyundai Accent, 1.5 liter, 5spd. The check engine light was on so it failed inspection, they said the inspection code was p1128 and it was most likley the 02 sensor, and my exzaust had a crack in it. So I had someone fix the exzaust and change the 02 sensor. I unplugged the battery and drove it the but the check engine light still came on. So I went to Auto Zone and they reset the computer. I drove it for about 30 miles so far and no check engine light, and before it came on at like 15 miles. How do you know when your car is ready. I thought by unhooking the battery it would reset everything, or was I wrong. Can someone give me some info please.
If the light has not came on by now you're set,....the car had to be driven, its called a trip cycle, so all the monitors could run their programming, if not you would get a code telling a certain monitor has not been completed, all vehicles from 96 and up have this done when the OBOII has been cleared of trouble codes....some takes longer than others and has to be driven in a certain manner, if you are unsure if this is not done yet, take it back to autozone and let them check it but tell them not to clear anything out.
Thank you for replying, but as soon as I drove it today the light came on. Besides the 02 sensor what other sensor could it be they can't narrow it to a exzact sensor thanks.
Is the O2 sensor an OEM part?, cause some of these aftermarket parts don't work, I went thru three of them that I got from autozone think that each one was faulty until I had the computer system checked out and with OEM sensor it cleared.