Thank you for replying! Yes my transmission is the electronic one. I understand that the throttle position sensor determines when to shift, but the fact that this is intermittent in nature is what baffles me. Doesn't the TPS either work or not? Not in between?
I don't have vacuum leaks, I had it smoked tested. I cleaned and tightened the grounds I have found.
As far as the transmission module, I was told they don't go out, so I haven't replaced it. Maybe I should....