Cel - P0140

[kansaslawguy]

O2 Sensor CKT no activity, (Bank 1, Sensor 2).

That's the code I received from the device at Autozone. My Box is a 2000 standard edition with about 53,000 miles. Through reading the forums, I've discovered that all of the O2 sensors should be replaced at approximately 60,000 miles, so I may just bite the bullet and have this done, but first, a couple of questions.

1. What does this code actually mean? Seems to me either the sensor is completely dead, or the electrical coupling might have come loose.

2. I turned the CEL off, and I'm going to watch the car over the next couple of days to see if it returns. If it doesn't return, am I ok to wait to replace the O2 sensor until it reappears?

3. Any other advice?

Thanks in advance to the knowledgeable posters of this board! I love my car, but know next to nothing about how a car actually functions.