Code result
P20F3
SCR NOx Pre-Catalyst Efficiency Below Threshold
Moderate severity
What it means
SCR NOx Pre-Catalyst Efficiency Below Threshold (Bank 2): the control module has detected this fault condition.
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 thermally aged
highOne of the most commonly reported causes for this code — check this first.
Related help
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