The average cost to fix an exhaust leak is around $100.00 to $360.00
The actual cost of fixing the exhaust leak depends on where the leak is.
If your muffler is bad then you need a new muffler instead of repairing it.
Or if you have a leak in the exhaust pipe sometimes it may be patched but other times you need a new exhaust pipe installed.
If the leak is in the exhaust manifold then sometimes an exhaust manifold can be welded back together and that would cost around $50.00 to $100.00
If you fix the exhaust leak yourself it can be cheaper.
You can drive with a hole in your exhaust and the vehicle will run and operate just fine.
However depending on where the hole is in the exhaust it could eventually leak exhaust gases and carbon monoxide into the vehicle.
If you get exhaust gases inside your vehicle you can get headaches and even pass out and die especially if the windows are up.
So it's best to have the hole in the exhaust repaired especially if it's underneath the cab of the truck or underneath a car that could cause the exhaust gases to get into the vehicle.
I have a small hole in my exhaust under my truck but it's under the truck bed so I don't exhaust gases in my vehicle.
The exhaust system is gonna get replaced soon anyway so I'm not fixing it.
However if it were under a car I would fix it to prevent the exhaust gases from getting into the vehicle.