o2 sensor not ready, catalist not ready, WTF

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I went to get my 40000mi new to me truck inspected today and it fails inspection because the o2 sensor and catalist is showing not ready. This will usually happen when either the battery has been disconected or a trouble code has been recently cleared, but after you drive for 50 or so miles everything should be ready again, I have had this truck for a month and have put 1100mi on it since. I have not disconnected the battery and today after the failed insp. was the first time a scanner has been connected to it, there are no codes showing anywhere, the cat is reading the correct temp. and the o2 sensor is showing the right reading, anyone ever see this? sounds alot like a bad computer