Buy one burger get one free!. Online coupon Code: BOGO24. In-Restaurant; 218723. Valid only at the KNOXVILLE Locations. Free burger includes base price of BYO or recipe burger (of equal or lesser value). Does not include extra charges. Cannot be combined with any other discounts, coupons, promotions, or Mooyah Rewards App Rewards. Limit one per party, per visit. No cash value. Expires