Put Put Out The Exhaust

[brim]

I figured it was maybe froma misfire at first

I've changed the plugs on the motor, that's nearly it though

I'm up on 95,000 now, when i start the car up it seems as if the exhaust give a little "put........... put" now and then

No engine codes, i can't really pinpoint it, I'd want to say clogged cat possibly? not totally certain however, looking for any other input