How to Unplug a Catalytic Converterby Francis Walsh
Catalytic converters are small, muffler shaped containers filled with platinum mesh screens that remove toxins from exhaust. In time, a catalytic converter will fill with deposits that stop exhaust from flowing to the muffler and out the tailpipe. When a catalytic converter gets plugged, the only way to unplug it is by removing the mesh screens that are blocked with deposit material. Unplugging a catalytic converter is easy, but there are regulations in some areas against operating a street vehicle with converters that have been unplugged.
Raise the vehicle so the tires are at least 24 inches from the ground when raised. Loosen existing exhaust pipes nearest to the catalytic convert so that the exhaust system has at least 1/2 inch of play (4-bolt flanges, exhaust hangers). Mark and cut the exhaust pipe so that there is 3 inches of pipe out the top and 3 inches out the bottom of the catalytic converter. Remove the catalytic converter from the car and take it to a flat work bench or table.
Secure the catalytic converter into a 5-inch tabletop vice so that the vice holds the catalytic converter in an upright position with one of the outlets toward the top, and an outlet toward the bottom. The bottom outlet should be placed onto one of the pine board blocks to support the converter when removing the inner mesh of platinum and clogged screen.
Insert the pipe into the top outlet of the converter until it is resting on the mesh on the inside of the converter. Rest the second pine board block on top of the pipe that is inserted into the catalytic converter. The pipe and converter should be in a position where it is easy for you to hit the block on top of the pipe that goes into the catalytic converter.
Strike the board on top of the pipe that is inserted into the catalytic converter sharply. The best way to remove the platinum mesh inside the catalytic converter is to turn the pipe a little after each strike. You can use the Saws-All to cut notches out of the end of the pipe that goes into the converter, which will act as teeth when struck with a hammer. Be sure that the converter shell is not being damaged when striking the pipe. You need to keep the outer shell of the converter free from holes to keep the exhaust system working without leaks.
Remove all the mesh inside of the catalytic converter by driving the pipe through from one end to the other. The mesh will break into little parts that will find their way out the bottom of the converter once the mesh has been entirely broken up. As more and more material is removed from inside the catalytic converter, the converter becomes unplugged and air will once again be able to pass through.
Examine the inside of the catalytic converter to be sure that as much of the material is removed as possible. Dislodge and pieces that may come loose later, and attempt to get all the mesh out of the converter before reinstalling. Remove the catalytic converter from the vice and bring back to the vehicle for installation.
Weld the unplugged catalytic converter back into the place it was removed, using a car jack or jack stand to get the car in position. Because the exhaust was loosened prior to removing the converter, the pipes can be moved to meet with the old converter's inlet and outlet pipes. Weld around the edges of each end of the converter inlet and outlet pipes to reinstall the converter.
- Tt he unplugging of catalytic converters with a pipe is a solution for fixing a catalytic converter for race or off-road applications, not street use.
Things You'll Need
- Catalytic converter
- Welder (130 amp)
- 2-by-2 inches diameter steel pipe
- 2 24-inch long 2-by-4 inch pine board blocks
- Wear eye protection and other safety gear at all times to protect from flying objects.
Francis Walsh has been working as a freelance writer since 2003. He has contributed to websites such as Shave, Autogeek and Torque & Chromeas, as well as provided content for private clients. Walsh has worked as a performance part-packer and classic car show promoter, now serving as crew chief for Nitrousfitz Racing.