Could it be my cat?

I've been dealing with an intermittent issue since I bout my foz about 2 weeks ago. The code that was given was for a knock sensor..so I replaced the sensor. Still had a code. Took it to Subaru dealer and had them run a log/diag on the car. It came up with two cylinders having reported misfires. I changed plugs and plug wires. Still have light and running issue where my motor will bogg down and become unresponsive to the throttle for about 3 seconds before it will get better and go back to normal. Ive been doing tons of research and with the past experience of a friend I now have a sneaking suspicion its the cat, even though I dont have any codes for it yet.... thoughts?:icon_frown: