If your vehicle is pulling in one direction, you may have a steering system or tire problem. A simple thing to check is the tire pressure. Use the tire placard to inflate the tires to the correct pressure. If the vehicle still pulls after you have inflated the tires properly, you may have a defective tire, worn steering component, or incorrect wheel alignment. If the tire pressure was the culprit, you need to determine why that tire lost pressure. You may have a nail puncture or faulty valve stem that is leaking air.