I have a Sienna 2002 over 8 years. I came back from a week-long trip and tried to drive out of airport parking lot. I realized that the car did not speed up smoothly as I was pushing the gas pedal slowly and noticed high RPM at low speed. As soon as I released the gas pedal, the RPMs went down and the car jumped to high speed. Since then, whenever I stop and go, I have these scary experiences. Is this a known problem or just me? Anyone have any ideas.