Nah, no loose heat shield. I brought the car into my shop on the way home from work one day and had the tech take a listen. Right away he suggested it was the heat shield and that they are known to come loose. I mentioned the previous owner had the shield tightened on about 3 occasions. A couple days later I took a baseball bat (the only thing with weight and handy at the time
) and rapped gently on the catalytic. The resulting sound seemed to come from within as opposed to the shield. Right then I had an inkling it was the converter. As soon as my tech got it up on the lift, he knew it WASN'T the heat shield. Anyways, I'm off to pick up the car right now. BTW, what is the expected life of a catalytic anyhow? I've got 84K miles on my ride.