1In resealable food-storage plastic bag, mix barbecue sauce, brown sugar, 2 tablespoons oil, the white wine vinegar, soy sauce, pepper sauce and 1 clove garlic. Add pork; turn to coat. Seal bag and refrigerate, turning pork occasionally, at least 2 hours but no longer than 12 hours.
2Heat coals or gas grill for direct heat. In large bowl, mix bell peppers, 2 tablespoons oil, the balsamic vinegar, salt and 2 cloves garlic. Remove pork from marinade; reserve marinade.
3Cover and grill pork over medium heat 20 to 25 minutes, brushing occasionally with marinade and turning once, until pork has slight blush of pink in center and meat thermometer inserted in center reads 160°F. Discard any remaining marinade.
4Cut pork into slices; arrange on platter with bell pepper mixture.