Here's a simple rule. If it will make the dealer money, it's NOT covered under CPO. If it costs less then $25 to fix, they'll do it as a courtesy. Here's another rule of thumb to keep in mind. If the car is still under warranty and you see wet hoses the dealer will declare 'no problem found'. If, the day after the warranty expires you ask them to check the same problem, there WILL be a problem found and it will cost $800 to fix.