Abstract: This invention describes a method of regenerating run-down or no longer efficient catalytic converters. The converter is cut perpendicularly to its axis in the area where the catalytic unit to be substituted is housed. The internal part of any residue of the catalyst that was inside is emptied and cleaned. The shell of the converter is filled with a helical unit without casing, either made of one smooth and one corrugated metal sheet overlapped and wrapped in a coil and treated after or before with washcoat and precious metals. The coiled bands are secured to the shell. The catalytic converter is reconstituted by joining and tig/mig welding together the two previously separated parts.