Valve timing question

Hi guys....I took my car to a mechanic to get the Water Pump freed up and a new Timing Belt fitted and he told me my Cam sprocket was a tooth advanced....after re-setting it back to normal, the idling is rougher and it lacks a bit of power...this seem strange? and should I get the sprocket advanced a notch again??....Help much appreciated.

Wayne

That's strange.. you should check out the timing for yourself. Being off a tooth is a very noticeable difference, and it sounds like your mechanic just put it off a tooth now.