Combine flour, lemon-lime beverage, & 2 tsp vegetable oil. Cover. Refrigerate 1-2 hrs.

Pour 2 inches of oil in skillet. Heat oil over medium heat until it is 365 degrees. Add enough potatoes as will fit. Do not crowd. Fry potatoes until outsides are brown, 4-6 minutes, turning once.

Drain wedges on paper towels; sprinkle with salt. Repeat with remaining wedges. Reserve oil to fry cod fillets.

Stir egg yolk into flour mixture. Beat egg white with electric mixer set on high in small bowl until small peaks form. Fold whites into flour mixture. Set aside.

Allow temperature of oil to return to 365 degrees. Rinse cod & pat dry with paper towels. Cut fillets into 6-8 pieces. Dip half of fish in batter. Fry until batter is crispy & brown, 4-6 minutes, turning once.

Drain on paper towel. Repeat with remaining fish.

Serve immediately with potato wedges.