why my 2003 ford explorer shuts off?

I have a 2003 ford explorer and it's been nothing
but maintenance. We replaced the battery, air filter,  
fuel pump, spark plugs, coils, manifold, fuel filter,
fixed the emergency gas sensor, air sensor. It's
basically brand new!! It starts fine, drives fine yet
when you drive and stop at a light it shuts off. It
shuts off basically when your not pressing on the
gas. We got the o2 sensors firestone said it was
fine. I absolutely hate this vehicle