DonCherry

Could be the speed sensor of your transmission.(You cannot fix it by yourself). Or the throttle position sensor or throttle body, which you can clean them by using electronic parts cleaner (can be found in CanadianTire). The throttle body is call 节气门。You can open the big intake hose, start the engine, spray the cleaner into it, do it until the inside of throttle body and plate clean; then remove the plug connect the throttle body position sensor, clean the metal contact parts. You can even remove the sensor from the body, do the cleaning.

If you cannot do it, go to garage (better go to dealer) and tell them the symptom.