Any check engine light? Any codes present? It sounds like you may have a bad idle air control valve. And as far as the vibration, that is very common on these cars and what I have discovered is that it is usually caused by the lower rear transmission mount going bad. But fix the high idle issue first. Try disconnecting the battery, first positive then negative for about 15 minutes, then hook it back up, first negative then positive and drive it for a day and see if it improves any.
SPONSORED LINKS
Saturday, February 15th, 2014 AT 3:50 PM