OBD-II reference

All 9.533 generic OBD-II codes, explained in detail.

Causes, inspection steps and sources — a comprehensive DIY archive. Created and maintained with love for the detail. Good luck and have fun!

Powertrain generic / SAE

P2274

O2 Sensor Signal Biased/Stuck Lean (Bank 1 Sensor 3)

O2 sensor at bank 1 sensor 3 reports a lean reading suspiciously stable for too long. Sensor 3 is typically downstream of the second catalyst on systems with three-stage aftertreatment.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number2 / 74

Possible causes

  • Sensor aged or contaminated high

Symptoms

  • Check engine light on
  • Increased fuel consumption
  • Possible rough idle or hesitation
  • Failed emissions test

Inspection / repair

  • Difficulty: medium
  • DIY: possible
  • Estimated cost: 80–500 €
  • Estimated time: 0.5–2.5 h
  • Component: oxygen sensor
  • MIL / check engine light
  • emissions-relevant

Sources

References

How to read OBD-II codes

The first letter names the vehicle system, the second digit distinguishes generic from manufacturer-specific, the remaining digits group fault area and number.

PPowertrain: engine, transmission, emissions
BBody: chassis trim, comfort, interior
CChassis: suspension, brakes, steering
UNetwork: CAN, control modules, communication