2002 Mazda Protege

Nice little sedan, Automatic, 4 cylinder, 159,000 miles, good gas mileage, Air conditioning, dependable, clean title, ready to go. I'm helping neighbor sell car. I've been mechanic on it for three years, and have done these things: Replaced radiator in 2020 when small crack developed in rad, (engine did Not overheat). Thought alternator had failed but it was badly corroded cable causing problem,( after I purchased replacement alternator). Replaced door lock mechanism on driver's door. Recently changed plugs and wires, coil, and fuel pressure regulator... Oil changed regularly.