# P0420 on the 2019 Dodge Durango

The bulletins listed name this code in NHTSA's summary, or are about the same components. A bulletin or a recall listed here may apply to the model year. None of it is a diagnosis.

Nobody has written a description of this code yet.

## Bulletins for this model year that name P0420

- [11020116](https://open.wenmarpro.com/bulletins/11020116), 2025-07-02: Flash: Powertrain Control Module \(PCM\) Updates \*\*Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): \*\* ● \*\*P0420 \- Catalyst System Efficiency Below Threshold Bank 1. ● P0430 \- Catalyst System Efficiency Below Threshold Bank 2.\*\* ● P0441 \- EVAP Purge System Performance \(for North America and Mexico markets only\). ● P0456 \- EVAP System Small Leak. NOTE: If DTC P0456 is present, use the wiTECH Small Leak Verification Test \(SLVT\) to determine if a leak is present in the system. In addition, the customer may experience the following: ● \*\*Vehicle fails emissions inspection testing due to OBD catalyst monitor readiness.\*\* This bulletin involves reprogramming the PCM with the latest available software.
- [11020115](https://open.wenmarpro.com/bulletins/11020115), 2025-07-02: Flash: Powertrain Control Module \(PCM\) Updates \*Customers must experience a Malfunction Indicator Lamp \(MIL\) illumination and the vehicle must exhibit/set one or more of the following Diagnostic Trouble Codes \(DTCs\): ● P0420 \- Catalyst System Efficiency Below Threshold Bank 1. ● P0430 \- Catalyst System Efficiency Below Threshold Bank 2.\*\* Customers may experience the following: ● Actual fuel economy reporting may not match the Instrument Panel Cluster \(IPC\). Other software improvements: ● Calibration update to address EVAP system emissions monitor readiness status accuracy. This bulletin involves reprogramming the PCM with the latest available software.