This leads to heat build-up and loss of power. Possible causes of a catalyst fracture are road debris striking the converter, loose or broken hangers, potholes or off-road driving. A catalytic converter will rarely fail without a problem or malfunction occurring somewhere in the emission system in front of the converter. It is important to determine what caused the converter to fail so that the problem can be fixed and to prevent a recurrence of the failure. Converter Meltdown. This is an example of a converter meltdown.