Thanks for the replies. Here is an update to the situation.
I replaced the pressure sensor and the harsh 2-3 shift went away. I had previously removed the Transgo resistor. I installed a Magnifine filter a few months ago.
I changed the filters with Wix products. While I was in there I happened to notice that some of the the cover plate screws had backed off and the cover plate on the valve body was loose on one end. I dropped the valve body and retightened all the cover plate screws with locktite.
I disconnected the battery when I did the maintenance and for the first week or so you could tell it was relearning. After that it worked great for weeks. Good, firm shifts. No hard 2-3 shifts. No 1-3 shifts. The transmission felt better than it has in a long time.
However, the last several times I've driven it it has started doing the 1-3 shift thing again. Sigh....

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My Jeep Liberty pageORM, air filter mod, and less restrictive exhaust has increased my 'everyday' driving 3 mpg.