I know of no product that can bring a catalytic converter back to life. Are you sure you don't just need to replace a oxygen sensor or two? Before putting out that kind of money I'd get a 2nd opinion.
I have a 1995 Camry wagon and still have the original converter. I agree with TurboJim about getting a second opinion. If you can find the fuse for the car's computer you could pull it and reset the computer and see if the code goes away. Or just disconnect the battery for a couple of minutes would I think do the same thing. Not too sure if that will work though. If you really need a converter it might be an interesting idea to get a used one from a used parts recycling center or "junk yard". Unless you really trust this mechanic from doing previous dealings with him/her I would be a bit skeptical.
Get under the car with a mallet or hammer and tap somewhat gently on the bottom of the cat. If you hear stuff in it rattling around, the cat needs replacement. This isn't a definite diagnosis, so if you hit it and you do not hear rattling, it does not mean your cat is good - but it's a good chance it may be the downstream O2 sensor in that case.
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