For a few years now my 89 has had an annoying tendency, when slowing down to come to a stoplight, etc. it will shift down to first but while continuing to brake to a full stop it will suddenly shift back up to 2nd then down to first again at about 15-20 mph. I've readjusted the TV cable with no change, it does kick down well and otherwise behave during normal driving. It does seem to do this since I had put a new BBK throttle body on a few years ago, but idle and everything else are adjusted correctly that I can tell. I had found an issue with bad idle caused by the BBK TPS so I put a new Motorcraft one on which fixed a lot, but not this. Also has a newer Motorcraft IAC and all intake-related sensors when I swapped in the Explorer intake. I don't see anything for this specific symptom in the shop manual so hoping someone has some troubleshooting tips.