There can be many reasons to walk away from a car. Maybe a check engine light it enough to dissuade you, but then again, maybe it’s not a deal breaker. It could be something simple as an O2 sensor, or possibly it’s a foreboding sign of what’s down the road. So, would you be willing to buy a car with a CEL?
If you were curious, that’s not my car, it’s from this comment here.