Code result
P0431
Warm Up Catalyst Efficiency Below Threshold
Moderate severity
What it means
The pre-cat (warm-up) catalyst on bank 2 has lost too much oxygen storage capacity. Its primary purpose — quickly reaching light-off after a cold start — is no longer met within the OBD limits.
Is it safe to drive?
Use caution
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
Pre-catalyst aged or damaged
highOne of the most commonly reported causes for this code — check this first.
Oxygen sensor drift
mediumA plausible cause — test and verify before replacing parts.
Related help
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