P2344
Cylinder 9 Above Knock/Combustion Vibration Sensor Threshold
What it means
The knock or combustion-vibration sensor monitors the structure-borne noise of each cylinder. The signal level for cylinder 9 has stayed above the diagnostic threshold for an extended period, indicating either persistent knock or an electrical fault that biases the channel high.
Is it safe to drive?
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
Persistent knocking on cylinder 9 (low-octane fuel, carbon deposits, hot spot)
highOne of the most commonly reported causes for this code — check this first.
Sensor or wiring biased high by short or moisture
mediumA plausible cause — test and verify before replacing parts.
Mechanical knock from bearings, piston pin or wrong torque
lowLess common, but worth ruling out after the more likely causes.
Related help
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