On 17 July, the ship headed back to Pearl Harbor for refit, which continued into the last week of August. She left Pearl Harbor again on the 27th, refueled at Midway on 31 August, and continued to waters northeast of Formosa off the Nansei Shoto. While passing northwest of the Bonin Islands to take up her station, "Bang" encountered an enemy convoy on 9 September. Diving to make a periscope attack, she fired a salvo at two loaded freighters, both of which – "Tokiwasan Maru" and "Shoryu Maru" – disintegrated due to internal explosions triggered by the hits. The escorts evidently sighted "Bang"s periscope and torpedo wakes, because as she dove deep, the depth charges accurately drove her down beyond her test depth to , where depth control almost disappeared. A pattern of 16 charges exploded directly over the boat, but "Bang" waited out her enemies. The escorts departed apparently satisfied that they had scored a kill, but "Bang" suffered only minor damage which her crew easily repaired. Three days later, she arrived on station.