Catalytic coverter problems

What is your question?

I got a check engine code for engine emissions. Was told it was the right side cat that needed replacing. The mechanic after starting finished with the job told me he had to change the left side not right. Fine...then not even a week later the car starts losing power and the check engine light comes back on goes off then back on again reading with the same code as before. Now I am looking at paying for this to be done again.Did he change the wrong cat?

How long has your 2014 Honda Pilot had this problem?

A few weeks total