o2 sensors and check engine light

2005 legacy

Check engine light was on and scanner said bad front 02 sensor on driverside. I replaced the sensor and check engine light was back on the next day.
Scanned again and code was bad o2 sensor front passengerside.
next day the check engine light was back on again along with cruise control light flashing.
Any ideas would be greatly appreciated, as each scan is costing me $ 42 as well as $ 130 each for the o2 sensors.

go to autozone or advanced auto parts its free....


Id take the sensor back it could be faulty