any one else have this problem?

my car only has 60K on it and already i have had to replace both Cats thank god for the warranty because these things cost about 800 dollars a piece, but im just curious to know if this is a widespread issue or just an isolated issue to my car?

I've had to change one of mine, but it didn't cost nearly as much as you say yours did. I bought mine and had it put on by the dealer and it cost $400.

But my car also has 138,000 miles on it...

mine cost me nothing.... gotta love warranty!

I don't know much about common problems on the 9g's, but to get a idea if its a "real" problem with the 9g's do some searching on the net or call around several Mitsubishi dealers around your area and ask if there is a service bulletin on cat converters on the 9g Galants. If you get a yes..then its a common problem and more than likely Mitsubishi has redesigned a cat converter to be replaced with the problematic original manufactured one.

If you read the owners manual. It states not to put the car in gear until the temp gauge shows a reading (the lowest mark)
This might have something to do with the temperature of the cats. If you give the car gas (as in acceleration) before the cats are up to optimal temp, they are prone to plugging up, instead of burning away carbon deposits. Just my 2 cents.

My cat went out at around 75k, due to a faulty spark plug that was misfiring..... I think chitownralli explanation is very good... Because upon numerous cold starts I would get a SES code and it felt like I had a slight difference in performance. This happened a couple times, so I was able to document each time the difference in performance.... After letting my car warm up even for just a minute or so, they code would go away and back to normal....

one of my cat whet out at just before I hit 50k. my warrantee covered it. I still have a rotten egg kind of smell from time to time.

Rotten egg smell is usually related to the sulfur in the gas. If you have a v6, premium gas is recommenced.

one of my cat went out at 48,000 miles. warranty covered it. It smelled awful.