Toyota Repair: 2002 Rav 4, best guess, code numbers

Question
I got a notice from Toyota that the "check engine light" staying on was a product of a fault in their computer system and that I could take it to an authorized auto repair dealer and they would fix it at no cost. I did. They fixed it but a month later, it came back on. I took it back. At first, the guy said it was the same codes but when I insisted that it was never fixed correctly in the first place, he gave me an estimate of $ 700 and said it was another part of the exhaust system. I should add that, at a seperate garage, I already had sensors fixed at a cost of $ 500 that caused the light to stay on.

Answer
Toyota has issued a "recall" (SSC 60I) that involves reprogramming the computer if there are the codes PO420/430, this is the fix to take care of this problem, without knowing what the actual code numbers were this is my best guess at this time, if the reprogramming was not successful then it may be necessary to replace the catalityc converter which is covered under the federal emission control warranty for 8yrs/80,000 miles.