What we normally call a cat is really a partical trap that catches soot and burns it off on a good run down the highway.
Have you checked the other normal problem areas
Do you actually have a driveability problem and if so have you checked for air on the fuel filter? If you have a 05 there were some that apparently had bad or incorrect fan clutches. They appear to be working but side by side to a working one it's night and day. One owner here actually has (had?) two and his heated up going up his long steep driveway and his wife's didn't. Another member, another set of eyes, and he sat them side by side and on the overheating one the fan was obviously not moving the same amount of air.
). When my CAT clogged on my 360 cu. in. Dodge 1500 engine, you could tell there was something wrong by the lack of flow coming out the back when you gave it a little throttle. Took her in to the shop and, sure 'nuff, the honeycomb had collapsed and clogged the cat.