Pontiac Repair: smell from exhaust, catalytic convertor, gm dealer

Question
Hi Todd, I have a 2002 GTP with 165000Km on it. When I step on it there is a smell from the exhaust, its like burnt hair or maybe rotten eggs if you get out quick and smell the exhaust. I can't really smell it if the windows are up, and it only happens if you drive hard, like passing someone(never happens if driven normal and goes away quickly#.
I think there is a slight rattle from the catalytic convertor if you hit it.Or could it be something else?
I changed gas stations a few times and it never made a difference. Would a catalytic convertor need replacement at 160000km?
You solved my misfire problem a month ago(new wires,fuel filter,plugs).The light never came on since.
I am leading towards getting a new catalytic convertor but if you can think of any other things the smell could come from, I would appreciate it.

Answer
Yup your right on. The converter is on it's way out with that may miles on it and add the fact that it was misfiring back a while ago it overloaded an already weak converter so I would venture to say that is what it is. I would however make sure it's running correctly I'd hate to ruin a brand new converter if the engine is running to rich an overfueling condition will kill a converter in a short period of time.. Just a note Down here in the states that car had a special policy on it I belive for an exteded period of time on the converter It was for up 120,000 miles. Not sure if that policy stands in Canada. here is the special policy # down here in the states. 05551 give it a try at your GM dealer and see if you can get it covered under that policy. Good luck :)