P0140 CEL Code
 

My 97 Mazda Millenia just pulled a P0140 code. From what I've read on this forum, that's caused by the OS sensor on bank 1 sensor 2. Question - Is this code likely caused by a faulty O2 sensor and I sould replace it or is this code indicative of another problem?

I appreciate any pointers/advice.

Thanks,
Fred