Why does my truck idle at 200 rpm?

An idle speed of 200 RPM is unusually low for most trucks, which typically idle between 600 and 1,000 RPM. This could be caused by a vacuum leak, a malfunctioning idle air control valve, a dirty throttle body, or issues with the engine's fuel system. It's advisable to have the vehicle checked by a mechanic to diagnose and rectify the underlying issue to prevent potential engine damage.