Will a 3.0L DOHC Duratec 30 V6 from a 2000 Sable fit in a 2003 Sable?

SOURCE: serpentine belt roouting

here you go

SOURCE: mercury sable 2001 duratec engine DOHC I get check engine light and diagnostic code PO401". Any suggestions?

Barring any vacuum leaks, P0401 is indicative of a bad EGR valve. Hope this answers your question. Best of luck.
Greg

SOURCE: Does my 2003 mercury Sable

Your vehicle has four oxygen sensors. There is a vacuum line underneath the throttle body that regularly fails, causing the lean condition, and the whistling and surging. Very dificult to see, but with the engine running usually you can fine the vacuum leak with your fingers. Hose is non-reinforced rubber, and is shaped in a 90 degree bend. If memory serves me right, it is the pcv hose. Replace this and your problems will cease.