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Code P0430 came up after stage 4 LMS tune


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Probably more than you want to know:



The Federal Test Procedure Catalyst Efficiency Monitor is an on-board strategy designed to monitor and determine when a catalytic converter has deteriorated below the minimum level of effectiveness in its ability to control exhaust emissions. This monitor relies mainly on the front and rear Heated Oxygen Sensors (HO2S) to infer catalyst efficiency based upon oxygen storage capacity. The front and rear HO2S switches are counted under specified conditions for the purpose of calculating a rear-to-front HO2S switch ratio. After the switch ratio is calculated, it is compared against an emission threshold value. If the switch ratio is greater than the emission threshold, the catalyst has failed. The oxygen storage capacity of a high efficiency catalyst will have a low switch ratio and high HC efficiencies. As catalyst efficiency degrades, its ability to store oxygen declines and it will begin to have a higher switch ratio and low HC efficiencies. In general, as catalyst efficiency decreases, the switch ratio increases. Inputs from the ECT, IAT and TP sensors are required to enable the Federal Test Procedure Catalyst Efficiency Monitor.


If the switch ratio is greater than the emission threshold, the catalyst has failed and a Diagnostic Trouble Code (DTC) is stored.

These are: P0420= Bank 1 Catalytic Convertor below minimum efficiency

P0430= Bank 2 Catalytic convertor below minimum efficiency

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