That seems to be what happens if you leave the Rear O2 installed because the PCM sees a result (signal) from the rear O2 when it runs the test. Now whether or not this happens the same for all model years is a question.
Mine is always at 14.7 no cat.
Sent from my XT912 using Tapatalk 2
Gremlins always seem to show up in pairs, or groups of three with our cars...