P0430

[P0430] The scan tool indicates Diagnostic Trouble Code (DTC) P0430: Front Catalyst system efficiency below threshold.

Description
This system evaluates the catalyst's capacity by means of the Primary and Secondary HO2S output during stable driving conditions. If deterioration has been detected during three consecutive driving cycles, the MIL comes on and DTC P0420 or P0430 will be stored.

NOTE: If some of the DTCs listed below are stored at the same time as DTC P0420 and/or P0430 troubleshoot those DTCs first, then troubleshoot DTC P0420 and/or P0430.

P0137-9: Rear Secondary HO2S (Bank 1, Sensor 2)
P0141: Rear Secondary HO2S Heater (Bank 1, Sensor 2)
P0157-9: Front Secondary HO2S (Bank 2, Sensor 2)
P0161: Front Secondary HO2S Heater (Bank 2, Sensor 2)

Possible Cause
- Front TWC or Rear TWC Deterioration
- Leakage in exhaust system