CREATE TABLE table_41669 ("Week" FLOAT, "Date" TEXT, "Opponent" TEXT, "Result" TEXT, "Attendance" TEXT)

Who was the opponent before week 5 that played on September 23, 2001?
SELECT "Opponent" FROM table_41669 WHERE "Week" < '5' AND "Date" = 'september 23, 2001'
SELECT "Opponent" FROM "table_41669" WHERE "Date" = 'september 23, 2001' AND "Week" < '5'