code po420 and po430 on 00gmc sierra 4.3l. could this be an ignition/plug/dist. problem

Question

my 2000 gmc sierra 1500 is reading code po430 and po420. the trucks runs rough when accelerating, almost like misfire or a skip. I replaced all the o2 sensors a few years ago. could this be a distributor/rotor or plug problem and not the cat. converters? please help

Answer 1

P0420 Catalyst system below effieciency (bank 1)

P0430 Catalyst system below effieciency (bank 2)

Runs rough when acclerating this is a misfire, When acclerating a high demand of ignition voltage is required, plug wires that are worn will allow ignition to seek ground. The purpose of the CK ENG LT is to protect the catalytic convertor, and the purpose of the catalytic is to protect the enviroment. In order for the catalytic to function properly a fuel ratio needs to be maintained having a misfire will take it out of it threshold, a properly maintained vehicle will see a long life of the catalytic convertor a misfire will surely lesseni ts expected life very quickly.Correct for the misfire before it is too late for the catalytic.