I'm fairly new to this forum, and gotta admit I have learned alot and look forward to checking in periodically to see what else I can learn. I have to say though, one of the first things I learned was we are not suppose to use the "D" word (lol-jk).
From what I know about code readers, yes they will only read one code at a time. Therefore, if both 02 sensors were bad at the same time, could it be the catalytic converter was what was throwing the code??