I've had my 2013 ES Lexus for 95K miles; it's at 146K. (This is my 3rd Lexus ES; had an Avalon before those). It's now experiencing several of these similar issues noted in this chain, in a much more exaggerated way. Mine tends to shutter in the upshifting behavior and while accelerating at about 15 MPH (and it seems to throw at me a split-second pause without either its proper fuel feed or its proper spark plug firing). It's also extremely frequent as it upshifts to 50 MPH during acceleration.
Have just recently started shifting up & down in the manual mode which seems to eliminate all symptoms. Since I really miss my old Standard Transmissions and shifting...and this doesn't require clutch work...making the best of it until I sort out what my next car will be. Maybe the car's memory will relearn from this new approach?? I'll let you know!
