so i finally got the car on ramps and checked out the exhaust system

and found what i think is the leak

the left pipe is the end of the manifold which goes over the other pipe with a small gap around the edge and its extremely sooty/black around it. So is this what could be causing the leak? i know it is coming from the front but it doesn't seem loud enough to be coming from just the manifold. Another thing i found is the muffler in the picture has two spots where it looks to have been patched but i can't find any holes in it