P22FDNOx Sensor Performance Slow Response High to Low Bank 1 Sensor 2
The downstream NOx sensor on bank 1 (post-SCR) responds too slowly when NOx levels fall after a reductant injection event. The control unit measures the time between commanded reductant dose and the resulting NOx drop and finds it exceeds the diagnostic threshold, indicating an aged sensor element.
Can I keep driving? With caution
You can drive to the shop, but do not postpone the repair. The problem may worsen and damage other components.
Sistema Afectado
Motor · Powertrain
La falla pertenece al grupo motopropulsor (motor y gestión electrónica).
Espacio para vendedores de repuestos
Aún no hay un anunciante en este espacio.
Symptoms You Will Notice
What you may observe when this code appears
- Check engine light or NOx warning on AdBlue/DEF level or quality warning Possible no-start countdown after ignore period Failed emissions inspection (NOx)
Possible Causes
The components or conditions that trigger this code
- 1NOx sensor element aged or thermally damaged SCR efficiency reduced (catalyst aged or contaminated) Reductant injector dosing drift
How to Fix It — Step by Step
Recommended diagnostic and repair procedure
- 1Difficulty: medium. Estimated time: 1-2 hours. Estimated cost: €400-€
- 2Professional repair recommended
Note: This information is for general reference. For precise diagnostics and safety repairs, always consult a certified mechanic.
Estimated Cost
Approximate range in USD (varies by region and shop)
Varies by diagnosis
* Diagnosis only: $50–$150
Quick Info
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