no, that has to do with the main mother board computer that runs all the electronics in the car, like all the sensors. i have heard that 04 trailblazers the PCM had a fault code that would mean nothing, i have only had one person tell me this, but i have the same problem and it dont seem to make it run different but it comes back every time i clear it.
Catalytic converter plugged?
catalytic converter circuit
P0420 is a Catalytic Converter efficiency failer. More than likely you will need a new Catalytic Converter.
P0420 bank one catalytic converter efficiency failure.
It might be the catalytic converter has overheated and had the honeycomb inside melt together.
There are two. One on the exhaust manifold and one just after the catalytic converter. If in doubt replace both. www.trailvoy.com Trailblazer enthusiasts forum
Perhaps a loose baffle in muffler Perhaps loose heat shield on catalytic converter
I went to a muffler shop and was charged $225 for parts and labor
catalytic converter
you can cut one of just about any car, but for what purpose for what car, for what diagnostic reason ?
Bank 1 is the upper oxygen sensor(s) before the catalyst (catalytic converter) bank 2 is the oxygen sensor after the catalyst (catalytic converter)
Bank 1 (pass side on this car) catalytic converter efficiency failure.