what does CPO mean on a listing

CPO means Certified Pre Owned vehicle that has been inspected from trained Technician. Also, you can get free warranty when you buy CPO cars.

A certified pre-owned car or CPO is a type of used car. Most often late-model, they differ from other used cars by having been inspected, refurbished, and certified by a manufacturer or other certifying authority. They also typically include an extended warranty, special financing, and additional benefits.