My ETS light has been coming intermitently for the past two months, possibly longer. Lately it's been on more than off. I took the car to my indy mechanic two weeks ago and he "cleaned out" the throttle body. The light didn't come on for about three days and then came back with regularity. The only symptoms other than the light is a slight, but consistant, hesitation that I notice at highway speed. The cruise control also won't work when the ETS light is on - guess it's somehow connected to the throttle body, which would make sense. Anyway, I'm going to shop around for a new throttle body on the internet. The best price appears to be at FCP Groton, however they are currently out of stock on the part. My indy will install the part and charge me for labor and new software installation. I'm expecting the total to be around $800 to $850. I'm not sure if that really addresses your question completely, but that's my related experience so far. Good luck!