Redlining

There are two things to consider. You did not list the right engine size so I cannot look up which throttle system you have. If you have a common sense cable between the accelerator pedal and the throttle body, that cable likely has lifted up and is hung over the quarter-round cable guide. That usually happens when the throttle is being held open by the cruise control cable and the accelerator pedal cable is relaxed. Simply reseating the cable will solve that, but also check that the cable does not have a kink in it that is helping it become unseated.

If you have the more dangerous "throttle-by-wire" system that put Toyota in the news a few years ago, the problem could be in the accelerator pedal assembly or the computer. The actuator itself usually does not cause a problem. This is not a system for do-it-yourselfers to get involved with.