2001 Durango codes P0141/P0161-need help

These codes are Sensor Heater Circiut Malfunction bank 1, sensor 2 and bank 2, sensor 2.
I cleared the codes and they came back on within 1 week.

Is there something else I should check before replacing both sensors? It seems strange that both sensors would be bad unless something else was causing the problem.

Thanks

there is a relay for o2 sensor heater circut, maybe thats it.