Replaced Cat, both oxy sensors and resonator. getting code 0134
 

I just replaces the cat converter both oxygen sensors and the resonator. At first I was only able to replace the number 2 Oxy sensor because they sent me the wrong #1. I received a code of 0140 saying the number 2 sensor was inactive. Now that I have replaced the #1 sensor I don't get the 0140 code but a 0134 code saying the #1 sensor is inactive.
Any ideas on what is wrong or what I should be checking. I also just changed the oil, trans fluid, fuel filter, coolant flushed and engine flushed.

1. Bad O2 sensor or wires.
2. The O2 sensor and mass airflow sensor comparison is misinterpreted by the ECM
3. The ECM could be malfunctioning in the O2 circuit