Hi, It does sound like ignition prob. I'm going to assume they've found fuel pressure good while fault's occurring or they wouldn't have replaced the (expensive) coils.
You may want to try a shop with factory info available - the "dealership" has equipment, software, and resources unavailable in the aftermarket. (Ie; diagnostic tools, computer tests, engineers' "hot line", and technicians' forums - like this one - exclusive to the manufacturer.
Saturday, February 28th, 2009 AT 9:05 PM