I get the P0410 code about once a month. This is a multiple error code, it has to happen several times before the check engine light comes on. Once the car runs without the error it resets itself.

I have an Ultragauge which warns me of "Pending Codes". The first one does not turn on the check engine light, the second in a row does. I can clear the error code with the Ultragauge and I'm good for a month. I'm thinking it is a worn relay contact on the RCM, since it is so random.