Exhaust leak??

Hi there I have a 01 Explorer 4.0 L V6, I botomed out a while back and think I might be having an exhaust leak that is getting worse, (if thats possible) I really can't describe the sound that it is making, but everything is running fine, if anything at all it is a little sluggish, The sound is coming from the drivers side, near the manifold or maybe the "collector" . If someone could tell me what an exhaust leak sounds like or how and engine would react, that would be a great help. also if I do have to replace the manfold, is it worth the extra cost to put on a header? I know JBA makes one for about 400$ or so, any advice would be greatly appericated, thanks

You need to put the vehicle on jack stands and look for damage. A bad leak you will notice. I would buy a manifold from a junkyard.