But you wouldn't buy a car with a check engine warning if you don't know how to read the code or fix it. For the most part you're not really looking for signs

But you wouldn't buy a car with a check engine warning if you don't know how to read the code or fix it. For the most part you're not really looking for signs of mechanical or electrical faults that will develop, you're looking for signs it has been cared for. Service history, clean interior, tires with decent tread, oil and water levels okay and aren't contaminated, starts up and drives nicely from cold to warm. That's about it. Someone with very little auto mechanic knowledge can do that. Sure an O2 sensor might give out in the next few thousand miles, but you have to allow for some maintenance cost beyond scheduled services for older cars.