Um. Well first of all pre-owned means someone had responsibility for it before you. Certification means a lot of different things every car dealership has a different method of certifying each and every car. Meaning one shop can do a good check and the next can put the keys in the ignition make sure it starts for them and well put a price tag on it. Whether or not it starts for you at home the next day is a different subject. Some car dealerships have warranties and some tell you to deal with the situation yourself. Sometimes if you get a Lemon (car that is supposed to be in good working condition but conks out after a day or so), there are laws to protect you so you can get your money back, sometimes that doesn't help. Make sure you have the car tested by someone you trust, unless you are sure those breaks will hold! LOL People are cruel and mean sometimes!