Are o2 sensors related to catalytic converter problems?

What is your question?

The car ran for two days, no problem. The third day it quit. We were told that coils needed to be replaced. Waiting to have a compression tester to test it. Could this be related to an o2 sensor also?

What makes this problem better or worse?

It wont crank at all

How long has your 2007 Kia Rio had this problem?

A few weeks.