1997 Plymouth grand voyager sputters on highway.

1997 Plymouth Grand Voyager SE 3.3l engine, when hot, engine sputters
at highway speeds, and when It comes to a stop, it stalls out. I have
replaced the spark plugs and wires, the fuel filter, MAP sensor, IAC, TPS,
and have cleaned out the EGR valve, EGR tube, replaced EGR gasket,
checked and replaced some of the vacuum lines where needed, changed
the water pump, and anti-freeze, replace the engine temperature sensor,
replaced the battery with new one, sanded down all the ground spots on
the motor and connectors, and still my mini van sputters when hot then
stalls at stops. Don't know whats next to check or replace. This mini van
has 194000 miles on it.