What would cause a 2003 Mercury Mountaineer to stall at idle?

A 2003 Mercury Mountaineer may stall at idle due to several issues, including a dirty or failing idle air control valve, which regulates airflow during idling. Other potential causes include a clogged fuel filter, fuel pump failure, or vacuum leaks that disrupt the air-fuel mixture. Additionally, problems with the ignition system, such as worn spark plugs or ignition coils, can also lead to stalling. Regular maintenance and diagnostics can help identify the specific cause.