What is causing reoccurring p0420 code?

Question

This vehicle has had 3 converters replaced will clear but monitors cat and evp will not reset then a few hundred mile code will come back. vehicle has only 65000 miles

Answer 1

There are few things that can cause the catalytic converter to fail:

• Leaking fuel injectors
• Cylinder missing due to bad spark plugs or ignition coil
• Low octane gas
• Aftermarket catalytic converter