P2270O2 Sensor Signal Stuck Lean (Bank 1, Sensor 2)
The downstream oxygen sensor on bank 1 reports a constant lean signal during a forced-rich command from the ECU. Suggests either a sensor that has lost its rich-side response, or a catalyst that is so degraded that no rich exhaust reaches the downstream sensor (cross-check P0420).
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 on Increased fuel consumption Possible rough idle or hesitation Failed emissions test
Possible Causes
The components or conditions that trigger this code
- 1Downstream sensor failed stuck lean Exhaust leak after catalyst
How to Fix It — Step by Step
Recommended diagnostic and repair procedure
- 1Difficulty: medium. Estimated time: 0.3-4 hours. Estimated cost: €60-€
- 2DIY possible
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
Dig Deeper
Videos, images and service manuals
Have Another Code?
Look it up directly: