Why would your car stall when you have the clutch engaged to slow down?

A car can stall with the clutch engaged while slowing down due to insufficient engine power or a lack of fuel reaching the engine. If the engine RPM drops too low, it may not maintain enough power to keep running, especially if the driver is not applying the throttle. Additionally, issues like a dirty fuel filter, malfunctioning idle air control valve, or a weak battery can contribute to stalling even with the clutch pressed.