SX4 O2 sensor stuck rich
 

Hello, I have a 2012 Suzuki SX4 with a 1.6L 16v engine and AWD. We bought it second hand from a lady that crashed it back in 2015. Took a few months to fix but eventually it was finished. Except a check engine light. My scanner said it was a heater cicrcuit inside the second O2 sensor on bank 1. Ordered the part and changed it and the old one was really broken inside (It's a Bosch O2 sensor with 4 wires). But since then I have a new error code that says: P2271 O2 sensor signal stuck rich and the car has higher fuel consumption and hesitates in upper revs (around 4000 rpm). Yesterday I took a new scan and it had the upper mentioned code and a new pending fault which said: O2 sensor signal stuck lean. Don't know what to do please help.