Hmmmm... my camaro did the same thing when the catalytic convertor was clogged...

It was fine for the first five minutes... then it got to the point where it would hardly accelerate. First dealership assessed it as a transmission problem, and replaced my transmission (under warranty <img border="0" title="" alt="[Big Grin]" src="images/icons/grin.gif" /> ). Did it again, and brought it back and they called me 15 minutes later and said my cat was horribly clogged.

I didn't want to pay $250 for the dealer to put a new one in, so I limped it to a buddy's house, and cut a hole right in front of it. Ordered an off-road cat and a week later the car ran like a champ.

<img border="0" title="" alt="[Smile]" src="images/icons/smile.gif" />