The P0133 code is for the bank one (passenger side), before cat O2 sensor being lazy & not switching fast enough, or as expected.

This could be caused by a number of things, like old O2 sensors, they do get slow to respond with age, an exhaust leak, a whiff of coolant will make em sick, or put them to sleep, a wiring problem to the sensor, are some of the things that come to mind.

So since this will mess with fuel trim, you may notice some diveability problems, mpg, ping/spark knock, cat, or exhaust manafold running hot, ect problems.

Seeing as how your ride has over 100K miles, it wouldn't be surprising if the O2 sensors are just worn out.

Yes you can reset the code & move the vehicle, or drive it some to see if it'll turn on again & it probably will.

I agree with powersmoked, I wouldn't ignore this warning & drive it much, like on a long trip, or hard, until you get things checked out.

I had the same code & changed both before cat O2 sensors on my 94 3.8L Taurus that had about 100k miles on it last year & had no problem removing them, as the factory had applied a high temp nickel anti-sieze compound to their threads, so be sure to add that to your replacements, if they don't come with it already applied.

My new ones had some pn the threads, but not much, so I applied more, just be careful & don't get it on the sensor part.

Seeing as how my sensors had 100k on them & directly affect fuel trim, I decided to change Both sensors, so the computer would have a matched set to work with.

Be sure to pull the B- battery cable to wipe the computers memory, so it can begin to rebuild new fuel trim tables with the new O2 sensors input.

More thouhts for pondering.
Let us know how it goes.