What's wrong with this picture Part 2, but much more serious this time.

Ooooof.
The time to fix that is NOW. Once the crack is buried under recently installed parts, it may be impossible to get a good weld on it.
Do you have any mobile muffler installation guys around there? That can be gas/torch welded. We have some mobile exhaust companies that travel around with trucks. They have tubing benders, torches and sometimes even a generator and 110 or 220v welder.