OBD code P130 - Check engine light

Hi all,

Recently, when I got this OBD code P130 I changed the O2 sensor 1 on the bank 1. After a month, I am starting to get the same OBD code again. The sensor is only one month old and it is genuine Lexus sensor. Do you think I have other fuel/emission problem or I just got the defective parts form the dealer?

Thanks for your help in advance.

Mo