I recently received my mother's used 2000 Toyota Camry. She had a lot of work done to it, including a " new" engine (rebuilt) and a new transmission. The car has been running great, except for today. While I was in line, picking up my daughter from school, I was in D, and the car was shaking. It would stop when it idled down. Then, as I was driving, it was shifting gears kind of " jolty", and when it downshifted from 2nd to first, it felt as though I was driving in a really low gear. When I got home, and was idling in the drive way, the RPM's dropped below 1 to about.5. They have NEVER been that low. I took off the O/D button, but I have no clue whether that would help or not.