Powertrain
generic / SAE
P20F3
SCR NOx Pre-Catalyst Efficiency Below Threshold (Bank 2)
The SCR catalyst on bank 2 is no longer reducing NOx within the required efficiency — downstream NOx remains too high relative to commanded dosing across a drive cycle.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / F3
Possible causes
- Pre-catalyst thermally aged high
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Inspection / repair
- Difficulty: hard
- DIY: shop recommended
- Estimated cost: 400–4000 €
- Estimated time: 2–8 h
- Component: scr pre catalyst
- MIL / check engine light
- emissions-relevant
Sources
References
sae:J2012