The ATX filter is inside the unit, and can't be replaced without dismantling the unit.
As far as the oil is concerned, I would stay with the 5W-30, unless you have a good reason to change.
95 Contour Zetec, ATX (wrecked, sitting in the barn)
95 Mystique Zetec, MTX
2000 Taurus SEL 3.0L Duratec
1994 Crown Victoria LX 4.6 V8
1993 Chevy Silverado 4.3 V6
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