https://www.carcarehacks.com/p1447-...ow-fault-causes-symptoms-and-how-to-fix/Just did a search and found this. Might be of use. It does describe possible causes not actually in the components, i.e. vacuum leaks etc.
In my case with the O2 sensors the Maxiscan live reading option with the engine running allowed readings from each sensor to be seen. The voltage reading showed which sensor was faulty. This narrowed it down to one of the two possible sensors, removing any confusion over which bank( left or right side of engine) was correct. The voltage reading on the faulty sensor was all over the place compared to the others that stabilised quickly.
Looks like you may have a process of elimination to find the cause of your evap fault! Good luck!
