Code result
P24F5
NOx Sensor Delayed Response - High to Low Bank 1 Sensor 2
Moderate severity
What it means
The post-catalyst NOx sensor on bank 1 (sensor 2) reacts too slowly when NOx in the exhaust drops from a high to a low level. Same failure mechanism as the upstream sensor — aged element, soot or condensate — but post-catalyst the consequence is a degraded SCR conversion-efficiency monitor.
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
Aged sensor element with reduced response speed
highOne of the most commonly reported causes for this code — check this first.
Soot clogging the protective tube
mediumA plausible cause — test and verify before replacing parts.
Related help
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