Final answer:
Carbon monoxide (CO) is the colorless, deadly gas in car exhaust fumes that can cause poisoning by reducing oxygen delivery to the body's organs. It is emitted from combustion processes, such as burning fossil fuels in cars.
Step-by-step explanation:
The colorless, deadly gas in the exhaust fumes produced by cars that can cause poisoning is carbon monoxide (CO). CO is emitted from combustion processes and is released when something is burned, such as fossil fuels in cars. It can cause harmful health effects by reducing oxygen delivery to the body's organs and tissues.