Cat converter...???

Ive got a '93 Probe and its been running fine but has been sitting for a year with monthly starts and oil checks and such...had to replace coil spring ...just got the spring replaced and was driving it and all of a sudden the exhaust gets loud I thought hum...bad muffler but its coming from the cat I was taking it the shop and now ive lost all power it wont hardly move could the cat be the reason for all this?

Yes it could.