2003 Dodge Caravan it shakes

If any of the cylinders are not firing you'll have a shake like this, it's very constant but usually misses at different times when you have a spark plug or ignition wire that is old or no good. Try replacing the plugs and taking a good look at why this occurred. I would put a scanner on it if you just had this done, a bad oxygen sensor will foul plugs. It is a common repair.