CPO (certified pre-owned) is most often a late-model used vehicle that has been inspected and certified by a manufacturer or other certifying company and typically includes an extended warranty.
However, there is no industry standard for what constitutes CPO certifications. There is also no industry standard for which items are inspected or qualified to perform a CPO inspection. A CPO can be very different from dealer to dealer and from manufacturer to manufacturer.
Most CPO programs come with some warranty. Be sure you understand what is covered and for what length of time before you purchase. All warranties are not the same.
Many used car buyers believe that a CPO vehicle comes with a comprehensive bumper-to-bumper warranty, only to find out they are responsible for repairs after the sale.
You must determine if the extra amount you pay for a CPO vehicle is worth the cost.
From: USA TODAY
Despite the benefits associated with manufacturer-certified used cars, consumers still need to be
careful. Consider these potential drawbacks:
1) There are no industry standards for certified used cars.
2) Dealer inspections may not be as comprehensive as a pre-purchase inspection or performed by Master Technicians.
3) While most experts will tell you that certification adds value to the retail price of a used car, it does not contribute to its eventual resale value.
4) Many financial institutions don't deem that a certified used vehicle is worth more than a used vehicle of the same year and mileage. You may need to convince the lender to loan you the additional amount.
5) Certification vehicles offer no guarantee that you will have fewer problems than a non-certified vehicle. Just because a car is certified, it is not better than any other well-maintained used car.
Compare the differences between CPO benefits on the sites below:
https://www.kbb.com/certified-pre-owned/compare/
https://www.edmunds.com/certified-cars/compare-program.html