I've been told that it doesn't matter which o2 sensor is upstream or downstream. Bank 1 or bank 2...and that they are all the same part number. Can that be true? Sometime I get a code that they are swapped.

 

Entirely possible. For some, the only difference is in the length of the wires..... they all operate exactly the same way. Getting a code that they are swapped? As in, seemingly reading the wrong side of the engine??? Unless the connectors for left/right are right next to each other, that should be possible....