Engine light on

DTC P0431
Code Definition

†DTC P0431: Warm-Up Catalytic Converter Efficiency Below Threshold (Bank 2)

DTC Set Criteria
DTC will set under following conditions: Engine speed is less than 3000 RPM. On 3.0L engine, Volume Air Flow (VAF) sensor output frequency is 69-156 Hz. On 3.5L engine, Volume Air Flow (VAF) sensor output frequency is 69-169 Hz. Intake air temperature is more than 14°F (-10°C). Barometric pressure is more than 11 psi (76 kPa). Throttle valve is open. On all vehicles, engine is in closed loop control. Vehicle speed is one MPH or more. Code will set if rear Heated Oxygen Sensor (HO2S) signal becomes similar to front HO2S signal. Monitor runs 84 seconds.

Probable Causes
†Catalytic converter deteriorated.
†HO2S failed.
†Powertrain Control Module (PCM) failed.