What else would cause the "Service Engine Soon" light reporting O2 Sensor?

What is your question?

I have replaced the Bank 1/Sensor 1 O2 Sensor twice now (NGK) because I thought the first one was defective. However, the light still comes on.

What makes this problem better or worse?

Code shows up again less than 50 miles after reset

How long has your 2004 Oldsmobile Alero had this problem?

About six weeks