I have a 06 Outback LLBean and recently I started having a problem. When it happens, the check engine light is on and the green "cruise" light turns on and off by itself, and cruise control does not work. Cruise was not being used when it happened (I rarely use the cruise). After the car is off and sit for a while or over night, the problem is gone. This has happened three times within a few weeks and I decided it's time to bring it to the dealer (I have extended warranty). Just got a call from dealer and they said they can not pin point the problem with the error code and the car is normal at this point. They suggested trying an engine cleaning/oil change which may clean some sensor and I'll have to pay for the procedure. It did not make sense to me and I turned down the suggestion. They said they'll try to keep driving the car for the rest of the day and see if the problem can be reproduced. My guess is I'll get the car back with nothing done and will have the problem again sooner or later.
Any idea what may be causing the problem and how I should deal with the dealer in this case? I understand it may be an intermittent problem and hard to diagnose but the extended warranty seems useless in this case