My 2000 Sienna with 175K on it is suddenly accelerating from a dead stop. Fast. The gas pedal pulls away from my foot, like it is on Cruise control.
Check the throttle cable linkage and spring.
Apparently you are not the only one who has had this issue. Google 2000 sienna acceleration issues. You should report the issue to the NHTSA. Maybe they will eventually issue a recall. You may also want to call a dealer and see if they will fix the problem at no charge. Be assertive, and good luck.
Search Toyota Sienna Questions
Toyota Sienna Experts
Related Models For Sale
Used Cars For Sale