I never had any issue with my first 06 G but my 08 G had the check engine light after ~200 miles (I would say under normal conditions). I took it to the dealer and they said they are going to replace some sensor (mentioned in the previous emails) which is on order so they just reset the warning lights. My first warning was only bank 1-5 warning but yesterday at ~2000 miles I had both banks in error. I called the dealer and I am scheduled to bring the car in soon for a quick check.
One interesting is that I have been complaining about to my dealer is the lack of power (compared for my first standard 06 G). I am not sure if this is something relating to this warning light or perhaps not familiar enough the new e-Grear.
Mehrdad