Code result
P221B
NOx Sensor 1/2 Correlation
High severity
What it means
NOx sensors 1 and 2 on bank 2 disagree by more than the allowed tolerance over a drive cycle. One sensor drifts, or there is a real NOx gradient that exceeds the calibrated map.
Is it safe to drive?
No — stop driving
This code points to a problem that can cause damage or affect safety. Avoid driving and have the vehicle diagnosed promptly.
Most likely causes
One sensor drifts
highOne of the most commonly reported causes for this code — check this first.
Related help
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