2001 Chrysler Intrepid

I went to a mechanic a month ago and replace the alternator because my battery light came on.  After about one month, the battery light came on again.  I went to the same mechanic and he said that the oxygen senor is faulty.  If I unplugged one oxygen sensor and I did not fix that one oxygen sensor. Will the car still run and won’t shut down?  What are the problems that the car might cause?