What does code P24F4 mean?

Q: What does code P24F4 mean?

NOx Sensor Delayed Response - High to Low Bank 1 Sensor 1. P24F4 indicates that the engine control module has detected an excessively slow transition in the nitrogen oxide sensor signal on bank 1 sensor 1 when the exhaust NOx level should be dropping from high to low. The sensor is responding, but its voltage or current change is delayed beyond the calibrated window, so the computer cannot trust the reading for emissions control.

DTC codes / P24xx · Auxiliary emission controls / P24F4

P24F4NOx Sensor Delayed Response - High to Low Bank 1 Sensor 1

P24F4 indicates that the engine control module has detected an excessively slow transition in the nitrogen oxide sensor signal on bank 1 sensor 1 when the exhaust NOx level should be dropping from high to low. The sensor is responding, but its voltage or current change is delayed beyond the calibrated window, so the computer cannot trust the reading for emissions control.

SystemPowertrain

Code typeGeneric (all makes)

SeverityMedium

Fix difficultyIntermediate

AreaAuxiliary emission controls

Guidance is general and written for all OBD-II vehicles. Exact tests and values vary by model, so confirm the fault before replacing parts.