I had the exhaust manifold gaskets replaced. I tightened the manifold bolts just a touch to verify they are tight. When the car is cold, I still hear "pu put put put". After a while it goes away but its definitly an exhaust leak. Where else should I look. I know it is coming from around the manifold area. Are there any other seals on any other parts or joints I should check? At idele or rev at idle, it does not manifest itself...only when in drive.....put put put put put