My 1992 Buick Century keeps jerking and shutting off intermittently?

What is your question?

It only happens intermittently otherwise it runs excellent. I'm guessing a bad Oxygen Sensor. Please respond ASAP. Thank you kindly.

What makes this problem better or worse?

Getting it up to 55 miles an hour or more.

How long has your 1992 Buick LeSabre had this problem?

2 months.