The engine control module has detected that the catalyst on Bank 1 is not reaching its required operating temperature within a specified timeframe. This typically involves a failure in the catalyst heating system or the sensor responsible for monitoring the temperature.
The sensor may be providing an inaccurate low reading or has failed internally, triggering the code.
The electric heater designed to quickly warm the catalyst is burnt out or malfunctioning.
Frayed, shorted, or corroded wiring between the sensor/heater and the control module.
A blown fuse in the heating circuit prevents power from reaching the catalyst heater.
An internal failure of the control module's driver circuit for the heater or the sensor input.
No. P0424 refers specifically to the temperature of the catalyst, whereas P0420 refers to the catalyst's ability to chemically treat the exhaust gases.
Not necessarily. This code usually points to the heating element or the temperature sensor rather than the catalyst substrate itself.
No. The PCM is very rarely the cause of P0424; the issue is almost always found in the sensor, the heating element, or the associated wiring.