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

P2576

Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Intermittent/Erratic

The DOR deterioration sensor signal jumps or drops out — typically loose connectors or chafed wiring near the radiator.

SystemPowertrain
Typegeneric / SAE
GroupP2
Range / number5 / 76

Possible causes

  • Loose connector high
  • Connector with intermittent contact under vibration low
  • Harness routed against vibrating component low

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: 60–300 €
  • Estimated time: 0.3–1 h
  • Component: dor deterioration sensor
  • Component: sensor wiring
  • 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