Hello my 2000 ford windstar with a 3.8L is misfiring,
Coil, plugs, and wires have all been checked checked coil by switching #6 and #2 and #3 and #4
when I disconnect the vacuum from the egr it makes no difference
when I disconnect the injector harness from injector #3 and #2 it changes nothing
I have cleaned all my egr ports
I have swapped injectors
and I also have coolant loss and random over heating, there is no smoke and no smell of anti-freeze
thanks for your help I am lost right now

 

codes are p0302 and p0303

 

Sounds like you could be in head gasket or intake manifold gasket land.
Since you should remove the intake manifold to access the head gasket what you find under the intake manifold may reveal the problem and not requiring any further disassembly of the engine.