Does my cat need to be replaced?

My car (2016 Kia rio) is throwing po420 (cat inefficient) and po304 (misfire), I have already changed the spark plugs and ignition coils. After I replaced those I drove it for about 5 to 6 days then I got a the po420 and po304 again. I have attached a picture of the exhaust of my cat and it looks fine to me. Do you recommend I wash the cat, replace the cat, or just replace the sensors?