Agreed. The trans fluid probably should have been changed every 60,000 miles unless it was lightly driven, so if it has never been changed, it is way overdue. I would drain and refill it, drive it a bit, and repeat. Maybe even drain and refill it 3 times to get most of the old fluid out of it. And use the correct Toyota Type IV fluid. I bought a case from the Toyota dealer for my son's car for about $65 or so.
From the owners manual:
â‘ Change automatic transaxle fluid every 60,000 miles
(96 000 km) if the vehicle is mainly driven under one
or more of these conditions:
− In heavy city traffic where the outside
temperature regularly reaches 90°F (32°C)
or higher.
− In hilly or mountainous terrain.
− When doing frequent trailer towing.
− Uses such as found in taxi, police or delivery
service.
If you do not use your vehicle under any of these
condition, the fluid does not require changing. See
Part D: Recommended Fluids and Lubricants on
page 6-19 for the proper fluid to use.
Good luck!