Rust is a problem no matter where you find it. But when it's the bolts and nuts on your exhaust system, it can be a little bit trying. There are multiple ways to remove a rusted bolt from the exhaust, and it will take time and patience to do it correctly.
Lift up the vehicle using the jack, and support the vehicle on jack stands. Make sure the vehicle is secure on the stands before you crawl underneath it.
Apply the penetrating oil on the rusted nut and bolt. You want the oil to soak the area where the bolt and nut connect on the exhaust, because that's what's holding things together.
Attempt to loosen the nut from the bolt using the 3/8-inch ratchet and sockets. If it doesn't come off right away, try using the 3/8-inch breaker bar to add extra leverage.
Place a fire extinguisher under the vehicle in preparation for the next step. Put on the welding gloves on as well.
Heat the bolt on the exhaust system using the Mapp gas torch. The penetrating oil may burn a bit, but it shouldn't cause a fire. Heat the bolt until it's red.
Try to remove the nut or bolt using the 3/8-inch ratchet and breaker bar. This should free the bolt from the nut, but if not, proceed to the next step.
Attach the angle grinder to the air compressor using the air hose, and cut off the nut and bolt. This is a last-ditch effort, but it will remove the hardware from the exhaust. Then you can replace it with new hardware.
