02 sensor

There is no such thing is an "oxygen sensor code". What is the code you are getting? A P0171 code, for example, would indicate "lean running", such as with an air intake leak, vacuum leak, MAF concern, air box concern, that sort of thing. When you say the code will not clear, how are you clearing it? Does the code go away when cleared and then come back after a drive? Or is this a code that is a "hard fault" -- which would lead me to consider some kind of wiring issue. What is a "code update"?