Corrected entry: In the episode "1A.M.-2A.M." Jack gives Yussuf the chip and tells him and Kate to take it to a specific meeting place and wait fifteen minutes for him before going to CTU. Jack is then caught and tortured to the point of death for about an hour. However, when he escapes, he goes to meet Kate and Yussuf. If they were following his instructions they'd have left well before then.