2000 Accord V6 CEL Catalyst or Spark Plugs/Wires

I drive a 2000 Accord V6 AT with about 108k miles. My check engine light turned on. I took my car to Honda and they told me I needed a new catalytic converter. They never explained why or what code they pulled. I then decided to take my car to Autozone and they told me that it was definitely NOT the converter but it was the spark plug wires. The autozone printout reads "Catalyst effeciency low-bank 1" and that it's either due to "Catalytic converter defective, engine misfire, large vacuum leak, or Engine oil leakage into exhaust-valve guide seals, piston rings". Does anyone have any information on this subject? I just want to know exactly what's defective so I don't have to spend money fixing the wrong thing. TIA
Take it back to you Honda Dealer they are right (Catalyst efficiency low-bank 1) this means your cat
is blocking and robbing you of power and fuel efficacy
But i would like to know what code #/#s you had .
Indy