dtf, check out my very similar thread on this topic. Same car, just about identical miles. After many headaches and dropping too much coin at two separate dealerships, it appears I finally found somebody who is diligent and pursued the problem as if they owned the car - something all too rare at dealerships. Can't say for sure in your case, but air in the fuel lines was my problem, and is problematic with this car apparently. He replaced O-rings and lines that were allowing air into the system when the car sits overnight. Picking it up tomorrow - have been without it for 1 month now. Unbelievable. But the one good thing after all this (besides all the wonderful advice on this forum), is that I seem to have discovered a highly respectable honest mechanic, who will now get my business from this point forward.