Loss of power on 2008 Nissan Altima Hybrid

I have been driving 55 miles/hour and the engine cut out and even by depressing the gas pedal there was no power, the cause according to nissan was BOTH of the catalytic converter need to be replace this was at 42k miles. Now at 92k miles, the engine power was lost at a stop light and nissan stated it was the converter inverter needed replacing. When I picked up the car after the repair within 15 miles the power cut out and the engine light and many others lit up. I brought the car back to the nissan dealer and they contacted the nissan engineers-no word yet on the cause. Any thoughts??

Asked by for the 2008 Nissan Altima Hybrid
I would ask them what is causing the cat converter to fail. Excess fuel causes the cat to fail, coolant or oil can cause premature failure. We would need to see trouble codes (all the trouble codes stored). Nissan had trouble ,not on the hybrid but other Nissans, (V6 Altima and Maxima).