Ya its 2" .I slapped on a cat back kit on mine the other day,and just said hell with the cat,no emissions here and 100 smacks compared to 12 for pipe and exhaust clamps.either way you go you will have to reduce the 2 1/4 cat back down to 2 inch, someone's gotta make a cat thats 2" inlet and 2 1/4 outlet if you gotta go that route,
good luck