My Legacy Brighten Wagon had a small surge while in either idol or driving. I took it to the dealer and they told me it was misfireing so they had to replace a coil and perform a tune-up. $700 and a week later it started again but this time it was worse and the car wanted to shut off. I took it back and they informed me it could be in need of a valve job but they weren't sure. Now after the valve job it is still having the same issue.