Code result
P2C7A
SCR NOx Catalyst Efficiency Below Threshold Bank 1 Catalyst 2
High severity
What it means
The ECM detects that the conversion efficiency of the second SCR catalyst on bank 1 is below the calibrated threshold. NOx slip past catalyst 2 is too high.
Is it safe to drive?
No — stop driving
This code can put the vehicle into limp or reduced-power mode. Avoid extended driving and have the vehicle diagnosed promptly.
Most likely causes
Catalyst 2 aged or contaminated
highOne of the most commonly reported causes for this code — check this first.
Reductant dosing insufficient for cat 2
mediumA plausible cause — test and verify before replacing parts.
Related help
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