"Cod" put to sea on her fifth war patrol 18 September 1944, bound for Philippine waters. She made her first contact, a cargo ship, Tatsushiro Maru (6,886 tons) on 5 October, and sank it. Two days later, she inflicted heavy damage on a tanker. Contacting a large convoy on 25 October, "Cod" launched several attacks without success. With all her torpedoes expended, she continued to shadow the convoy for another day to report its position. In November she took up a lifeguard station off Luzon, ready to rescue carrier pilots carrying out the series of air strikes on Japanese bases which paved the way for the invasion of Leyte later that month.