Fuel pump damaged catalytic converters on 2006 Nissan Armada

Service engine light came on a month or two ago. Failed state inspection report indicated both catalytic converters failing. Dealership says that although they replaced the catalytic converters less than 1 year ago, they need to be replaced again, along with the fuel pump, which was just recently replaced (by another shop)after a problem with chugging, shuddering, dying (even in motion). I took it back to the other shop, and they said nothing wrong with it, turned off the check egine light and offered to get it inspected (suspicious). The mechanic says that the fuel pump cannot damage the catalytic converters and that Nissan service is taking me "for a ride". ?????? Don't know who to trust here. Any similar experiences with fuel pump and catalytic converter?

by in Austin, TX on November 20, 2010
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1 answer 1 comment
ANSWER by , November 20, 2010
The fuel pump has nothing to do with the catalytic converters.The only thing that will plug a converter is coolant or oil.If you just replaced your fuel pump there should be a warranty on it.
COMMENT by , November 21, 2010
Anything that can cause the engine to misfire or thow off the air fuel ratio can and will damage the catalytic converter including the fuel pump.