My 2004 XC90 shows a check engine light with a P0050 - HO2S Heater Control Circuit Bank 2 Sensor 1 code. I was told the Bank 2 sensor 1 was the sensor on the passenger side close to the firewall. I changed out the sensor and cleared the code. The check engine light came on again and shows the same code. I need to know if I changed out the correct sensor. If I did, what else could be causing the P0050 code?