Chevrolet Silverado 1997 pick up

Question

P430: catalyst system efficiency below threshold (bank 2) I changed 2 sensors and replaced spark plugs, what else can I do? how do I know if the catalyst converter is bad?

Answer 1

Hi there,

You need a scan tool that can read the rear O2 sensor voltage. Get the engine up to temp, then compare the sensor readings on bank #2, both the front and rear O2 sensors. If they mimmic each other then the converter is not doing it's job and needs to be replaced.