Toyota Repair: catalytic converter 2001 Corolla, air flow sensor, catalytic converter

Question
My "check engine" light has been on for almost 2 years.  I took the car to two different dealerships.  The first said I needed a catalytic converter so I went to another dealership for service and they said I needed the air flow sensor replaced.  I had the sensor replaced.  The check engine light came on again about five months later and the second dealership said I need a catalytic converter.  I've driven a Honda that needed a catalytic converter and this car is not riding rough at all.  Could this be a Toyota scam?

Answer
I don't think so, if the check engine light trouble code is a PO420 then the catalityc converter is the problem, if you reside in the US the converter is covered under the federal emission control warranty for 8yrs/ 80,000 miles and if that's the case it is replaced at no charge to you.