Catalyst Converter Problem....

[8500lbs]

I have the Dyna Tech high flow cats and I have less than 50,000 miles one them. I thought they were great untill yesterday when they tripped the engine light three times. it is P0420 or insufficient flow. Not sure what the deal is but i am going to try and call Dyna tech and have them replaced. ig it is a no go then i am going to strip them and look for the censor chearters. Does any one know or recomend a place to get them from,

Thanks
B