Is this code only for the Upper O2 sensor?

 

You know that once one O2 sensor goes, the other one will likely go within 6 month.....

 

What is the code for the lower one?

This is strange these have to be replace at barely 60K. I have been told they should go over 100K

 

O2 sensors can go bad at any time but most of the time they last longer than 60K miles. The earliest I've had one need replacing is at around 80K miles. Another car managed 132K miles on its original sensors.

No O2 sensor experience with my MINI but my experience with previous cars is if one sensor is acting up, triggering a CEL, I replace all O2 sensors. Most of previous cars have been either V8 engines or flat 6 engines with two cylinder banks and 2 sets of #1 and #2 O2 sensors. So I replace all 4 sensors. My thinking is while one is bad the others have lived the same life and while not "failing" are nearing the end of their useful life. I'd rather replace them all at one time than to have to get the car back in the shop 3 more times to replace each of the other sensors as they go bad.

 

My same experience. Their life depends on what has come through the muffler to some degree. Since they share the muffler stream, they have "shared any abuse as well". My experience is also the one higher exposed to more heat goes first and the one further down in the stream goes later. I am only at 65K in my mini so I have not replaced yet, but I have read lots of threads where people are searching like you are talking about on which one and if you read all the way through thread they end up replacing them both before they cleared the code. So I'm guessing it is not straight forward as to which one. My experience with replacing them before was not the cost but the time to get them out.

The P Code is a generic code. I'm sure if you hook up a BMW specific code reader it will tell you exactly which O2 sensor. You can buy one from $100-150. Of course, that is probably at or more than an O2 sensor I'm guessing.