Powertrain
generic / SAE
P2097
Post Catalyst Fuel Trim System Too Rich (Bank 1)
Long-term post-catalyst fuel trim on bank 1 has reached its rich limit. The downstream sensor sees more reductant than expected, often pointing to a degraded catalyst that no longer stores oxygen, or a failing downstream sensor biased rich.
SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number– / 97
Possible causes
- Catalyst oxygen storage exhausted high
- Downstream sensor biased rich 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: possible
- Estimated cost: 60–1500 €
- Estimated time: 0.5–4 h
- Component: oxygen sensor downstream
- Component: catalytic converter
- MIL / check engine light
- emissions-relevant
- drive cycle required
Sources
References
sae:J2012