High RPM and wont change gear

[emmagail]

I everbody
i have just inherited a 2006 Grand caravan and having immediate problems!
i hade a 406 code but today everything went funny
i was driving and had no power, the revs were up at 3000, very slow to change up gears.
When i got home I smelt something odd and thought I saw a plume of smoke when I restarted

any suggestions people
thanks