What r the symptoms of a bad catalytic converter or it going out?

What is your question?

My check engine light was on when I leased my Tahoe about a month ago. We had it out on computer one code came up for o2 sensor we replaced a week ago. The following Monday the check engine light came back on this time it's reading 6 codes all for o2 and knock sensors most say low circuit.. Then last Friday drove all around didn't act up till headed home with a/c on high and about 100 outside. Then it started sputtering, the TAC went down wouldn't go over 20 mph. Then stalled and battery died.. Need help