I just got this car not 1 week ago. It's been driving absolutely fine, my gas mileage has averaged about 24 mpg and it's been quiet and smooth.

All of the sudden when I just tried to start my car it wouldn't start. After 4 tries it finally starts and it's rumbling like a Chinese earthquake. The Check Engine and Trac Off lights are on (The check engine is blinking).

The car now has no acceleration power; it takes me about 30 seconds to get to 45 MPH.

I drove for a few miles and then came back home. When I looked underneath the car, the catalytic converter (or whatever the first bulgy cylindar on the exhaust pipe right after the Engine is) looks all dirty and there are big beads of black sludge dripping from all over it. It looks like melted black plastic.

If I turn on the AC while the engine is running the engine revs up a little and then instantly shuts off.

I did a little research and the symptoms match Cat Converter failure pretty well but I don't understand how it could happen INSTANTANEOUSLY! My car has been driving fine and I drove it around town just 4 hours before getting back into it, nothing seemed wrong. Now, out of nowhere, it's practically not drivable.

Any help would be greatly appreciated.

It's a 2003 Olds. Alero with 4 Cylinders. I don't know if it's GX or GL, the dealer didn't even know (I have automatic headlights and a trunk opening button).

77k miles. Oil is full up and clean; all fluids are topped off.

Thanks in advance.

EDIT: I just drove for a few more miles and then looked under the car. Part of the catalytic converter closest to the back end of the car is glowing red with heat.

 

There is definitely something in the cat preventing the exhaust from passing freely through it. It sounds like a piece of the cat broke off internally and is plugging the exit pipe. This can happen suddenly. The only solution is to replace the cat, sorry.
I would also look around and find the source of the sludge. The cat may have gotten so hot it melted something nearby.