Is it necessary to change the coils even though they are running good in an 04 3.0L?

 

NO! just keep a few spares in the trunk....

 

From what i have found at the dealer the main causes of failures on 3.0L coils are pressure washing the engine, and using a screwdriver or small pry bar to pry them up to change the plugs. Don't wash your engine around the coils, and only pull up on the coils by hand to change the plugs and you should never have to change a coil.