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DTC codes / P22xx · Fuel and air metering (injector circuits) / P22FA

P22FANOx Sensor Performance - Slow Response High to Low (Bank 1 Sensor 1)

P22FA means the engine computer has detected that the nitrogen oxide (NOx) sensor on bank 1, sensor 1 is responding too slowly when the exhaust oxygen level drops from high to low. The sensor's signal should switch quickly, but the computer sees a lazy or delayed transition, so it flags the sensor's performance as out of specification.

SystemPowertrain
Code typeGeneric (all makes)
SeverityMedium
Fix difficultyProfessional
AreaFuel and air metering (injector circuits)

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

Running on fumes Free guides aren't free to make. Top up the tank. Any amount, one time. Fuel the Garage