P2577
Direct Ozone Reduction Catalyst Efficiency Below Threshold
What it means
The DOR catalyst no longer reduces tropospheric ozone with the required efficiency, based on the deterioration sensor and operating-time model. Coating worn off the radiator surface, contaminated by road salt and grime, or thermally aged after many heat cycles. Replacing the affected radiator/coating restores function.
Is it safe to drive?
The vehicle is usually drivable for short distances, but the problem can worsen or affect emissions. Diagnose and repair as soon as practical.
Most likely causes
DOR coating worn off the radiator
highOne of the most commonly reported causes for this code — check this first.
Coating contaminated by salt and grime
mediumA plausible cause — test and verify before replacing parts.
Related help
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