Powertrain
generic / SAE
P2BA4
Catalyst Feedgas Performance
The ECM detects that the exhaust gas composition reaching the catalyst (feedgas) deviates from the calibrated profile. Pre-cat O2 measurement and air-fuel control are inconsistent with engine operation.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / numberB / A4
Possible causes
- Long-term fuel trim drifted out of nominal range high
- Exhaust leak upstream of catalyst medium
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Inspection / repair
- Difficulty: medium
- DIY: shop recommended
- Estimated cost: 200–1500 €
- Estimated time: 1–6 h
- Component: catalytic converter
- Component: o2 sensor pre cat
- Component: ecm
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012