When driving (especially accelerating) our 09 Outlook down the road, it bogs down and shutters, and the check engine light blinks. I'm sure it's misfiring, maybe because a plugged fuel injector or bad gas(?). OnStar said they couldn't find any problems when performing a diagnostics check. It's going to the dealer tomorrow, for tire rotation, oil change, headlight recall, and now this, but I was wondering what it could possibly be, and if it means spending an arm and a leg. Thanks!