Powertrain, generic (extended)

P2576 Direct Ozone Reduction Catalyst Deterioration Sensor Circuit Intermittent/Erratic

Check engine lightOn
EmissionsRelevant
Drive cycleNot required
Limp modeNo

P2576 describes a deterioration-sensor signal on a direct ozone reduction (DOR) catalyst that comes and goes or jumps without a physical reason, rather than staying low (P2574) or high (P2575). Loose terminals, a cracked connector housing in the airstream ahead of the engine, or chafing where the harness meets the radiator are typical suspects, since that spot sees vibration, spray water and road salt. No manufacturer documents P2576 publicly. CARB's DOR rules describe what such a sensor would watch, and BASF positions its PremAir NXT radiator coating for the 150,000-mile durability that Tier 3 and LEV III demand. A stored code does not affect cooling or performance but counts as an emissions fault.

Likely causes

Loose or corroded terminal in the sensor connector
Harness chafing at the radiator support
Cracked connector housing letting water in

Symptoms

  • Check engine light, possibly only now and then
  • No noticeable driving symptoms

Repair estimate

DifficultyMediumWorkshop job
Parts and labour€30–900
Time0.5–3 h

Typical range across vehicles; the real cost depends on what the testing finds.

Parts involved

dor deterioration sensorsensor wiring

Related codes

P2572P2573P2574P2575

References: law.cornell.edu, basf.com.