Hi Leeann...............
You hit the nail right on the head, my Cat had ceased puuring. I took The Blazer in for diagnosis and it showed just about every problem there is with the exhaust emission system, but the mechanic was honest enough to tell me to get a new Cat fitted first and then he would check again. My Cat had a BALL of carbon rattling around inside! Anyway, with the new Cat it pulls like a dream, and the mechanic tells me my gas mileage should improve dramatically.
Thanks for taking the time to respond...............