Code result
P21B5
NOx Adsorber Over Temperature
Moderate severity
What it means
A temperature sensor at the NOx adsorber on bank 2 reports a value above the safe limit. Sustained over-temperature destroys the storage washcoat.
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
Runaway desulphation regeneration
highOne of the most commonly reported causes for this code — check this first.
Related help
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