+1,!! A fresh fuel filter is always a good start..And regardless if it was the problem or not..Its new and one less thing to worry about!
But the cats are important..Ive seen cats after 230,000 miles and they looked new. Also seen cats with 50,000 miles and 3/4 clogged,
Many things can get them shitty, Bad fuel, exhaust leak for a long period of time,etc...