CREATE TABLE table_17467578_1 (original_airdate VARCHAR, us_viewers__million_ VARCHAR)

What was the original airdate of the episode 'The Cold Turkey', which was viewed by 3.73 million viewers?
SELECT original_airdate FROM table_17467578_1 WHERE us_viewers__million_ = "3.73"
SELECT "original_airdate" FROM "table_17467578_1" WHERE "3.73" = "us_viewers__million_"