2000 Ford Taurus Car Dies When Idling

The check engine came on so I had someone read the codes. I do not remember the exact codes but there were three. Bank1, Bank2 and EGR Flow errors. I was told the Bank1 and Bank2 errors indicated a clogged catalytic converter. The car would idle rough and it got worse up to the point it would die. I took a look under the hood and discovered that the ninety degree piece of hose coming off the PVC valve was almost in two pieces. I replaced the hose and the valve and the problem seemed to go away. A few days later it died again while idling. Now it will idle fine until you turn the AC on, then it dies. The car is not running any hotter than usual. Can a clogged catalytic converter be diagnosed (by a non-mechanic)? I was told the car had two catalytic converters and I should replace both of them since I would not know which one it was. Is that true? Could the issues I described be caused by something else?