P1149 PCM Code Question

:frog:I've had a recurring problem where my PCM is throwing a P1149 (O2 Circuit Range Fault). After reading the code and often either pressing on the O2 sensor connector, or uncoupling and recoupling it, the MIL (check engine) light goes off for about 3 months. Then, usually during or after a rain storm, and often during highway driving, it goes back on. This last time, I did all that; it stayed on for about a day and then went off. Also, for the past two days while it was on, I would often hear a wherring noise from the back right side of the car (fuel tank, fuel pump?) when I hit a bump with the right front or rear tire. This also seemed to go away today after the MIL turned itself off. Any ideas about what could be going on? I've got about 60K on the car; I thought O2 sensors just go out, is it common for them to act like this as they begin to fail? The sensor is a bit on the pricey side (about $100), so I'd like to avoid replacing it if I don't have to yet.