It probably takes R134-A refrigerant. You can buy it at Wal-Mart. Look under the hood for a sticker that tells what kind it takes and how much. If it needs refrigerant, that means there is a leak. You really need to take it somewhere and get that fixed. Unless you have some kind of extended warranty on your car, you should take it somewhere like Tires Plus or Tire Kingdom. The dealership will charge more.