Diagnostic Trouble Codes (DTC) P0430 and P0431 indicate that bank 2 catalyst system efficiency is below the acceptable threshold.You have not:
(1) Refueled vehicle with leaded gasoline.
(2) Noticed high vehicle oil consumption.Possible causes:
-- Use of leaded fuel.
-- Oil contamination.
-- Cylinder misfiring -- Check for bad spark plugs or bad plug wires. This may have been a pre-exisintg code? Spark timing retarded below specification can increase exhaust gas temperature and decrease catalyst efficiency over time.
-- Damaged HO2S - Incorrect HO2S signal input (e.g. rich/lean input signal when the engine is operating under lean/rich conditions) can cause an abnormal temperature increase in the catalyst.
-- Damaged ECT sensor - ECT sensor DTCs can indicate that the thermostat is not operating correctly or that the engine coolant level is not filled to specification, producing above normal operating temperatures.
-- Downstream HO2S wires improperly connected.
-- Fuel pressure too high - compensation for a bad FPR.
-- Damaged exhaust system pipe.
-- Damaged exhaust manifold.
-- Damaged muffler/tailpipe assembly.
-- Damaged catalytic converter - Internal deterioration of a catalytic converter is usually caused by abnormal engine operation upstream of the catalyst. Events that can produce higher than normal temperatures in the catalyst are particularly suspect. For example, misfiring can cause higher than normal catalyst operating temperatures.