P2341: Cylinder 6 Above Knock/Combustion Vibration Sensor Threshold
What to do
Avoid heavy loads and ease off if you hear a rattle. Ask how many cylinders are reporting. If it is only this one, the cause is something about this cylinder — its injector, its plug, its deposits. If several are, the cause is shared, and exhaust gas recirculation is worth checking specifically: recirculated exhaust cools combustion and suppresses knock, so a valve stuck closed or a passage blocked with carbon raises knock on every cylinder at once.
What this code means
Cylinder 6 is requiring more knock protection than normal. The mechanism is at P2336.
This is the right place to restate the discriminator the whole family rests on, because by six cylinders a code list can contain several of these at once.
- One cylinder above threshold points at that cylinder: its injector, its plug, its deposits, its local cooling.
- Several or all cylinders above threshold points at something the engine shares, and the list is short and mostly cheap: fuel grade, base ignition timing, intake air temperature, coolant temperature, and exhaust gas recirculation.
Recirculation deserves naming explicitly, because its role in knock is not obvious. Exhaust gas is inert — it has already burnt. Feeding some of it back into the intake dilutes the charge and lowers peak combustion temperature, which directly suppresses knock. That is a large part of why the system exists, alongside its emissions purpose. So an EGR valve stuck closed, or a passage blocked with carbon, raises knock across every cylinder at once, and it is a far more likely explanation for a whole-engine pattern than six simultaneous injector faults.
So the first question to ask of a knock code is not which cylinder but how many, and the answer changes the entire search.
Likely causes
Start here
- Stuck EGR valve · moderate
- Blocked EGR passages · moderate
- Incorrect or low octane fuel · easy
Less common
- Carbon deposits in the combustion chamber · moderate
- Clogged fuel injectors · moderate
- Faulty intake air temperature sensor · easy
Symptoms
Components involved
Information, not instruction
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Community experience
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