OBD-II code · Powertrain (generic, extended)
P2099 Post Catalyst Fuel Trim System Too Rich (Bank 2)
Bank 2 counterpart of P2097. Post-catalyst trim on bank 2 has reached the rich limit — usually a depleted catalyst or a downstream sensor biased rich on the bank 2 side.
Is it safe to drive with P2099?
Usually safe to drive in the short term. Get it diagnosed when convenient, sooner if the car drives differently.
Common causes
- Most likelyBank 2 catalyst oxygen storage exhausted
- PossibleBank 2 downstream sensor biased rich
Symptoms
- Check engine light on
- Failed emissions inspection
- Possibly slightly increased fuel consumption
- Sulfur (rotten egg) smell from exhaust under load
Repair at a glance
- Difficulty
- Medium
- DIY friendly
- Often, with basic tools
- Typical labour
- 0.5–4 h
- Emissions test
- Likely to fail
- After the fix
- A drive cycle is needed before the light stays off
- Parts involved
- Oxygen Sensor Downstream, Catalytic Converter
Related codes
- P2097Post Catalyst Fuel Trim System Too Rich (Bank 1)
- P2096Post Catalyst Fuel Trim System Too Lean (Bank 1)
- P2098Post Catalyst Fuel Trim System Too Lean (Bank 2)
- P209AReductant Injection Air Pressure Sensor B Circuit
- P209BReductant Injection Air Pressure Sensor B Circuit Range/Performance
- P209CReductant Injection Air Pressure Sensor B Circuit Low
Code data: OBDex open dataset (CC0). Labour times are typical ranges, not a quote.