A ninth cylinder exists only on V10 and V12 engines, so P2344 is confined to a small group of vehicles: V10s such as Ford's 6.8L Triton in E-Series vans, Super Duty pickups and the Excursion, the Dodge Viper and Ram SRT-10, and performance cars from BMW, Audi and Lamborghini, plus the V12s. The code means the knock control has found the vibration level in cylinder 9's combustion window above the limit and is retarding that cylinder. No manufacturer was found that documents P2344 publicly; GM and Saab handle single-cylinder knock under P0324 instead. The usual suspects are deposits, fuel grade, plug, injector and noise sources near the sensor of that bank, examined for cylinder 9 specifically.
Medium severity. Can I keep driving?You can drive in moderation without pushing the engine. If you hear knocking, avoid full-throttle acceleration.
Cylinder 9 is numbered according to the manufacturer: check your engine's manual before working on it.
Symptoms
- MIL on
- Knocking or pinging under heavy load or towing
- Reduced power
Most likely causes
- Deposits or hot spots in cylinder 9
- Fuel of too low octane for a high-output engine
- Wrong or fouled spark plug in cylinder 9
What to check, in order
Start with the simplest. You can tick off each step.
Good to know
- Repair difficulty: medium
- It affects emissions.
What each character of P2344 means
- P: Powertrain: engine and transmission
- 2: Generic code: same on every make
- 3: Ignition and misfires
- 44: Specific fault in that system
Frequently asked questions
Can I keep driving with code P2344?
You can drive in moderation without pushing the engine. If you hear knocking, avoid full-throttle acceleration.
What causes code P2344?
The most common causes are: deposits or hot spots in cylinder 9; fuel of too low octane for a high-output engine; wrong or fouled spark plug in cylinder 9.
Related codes
- P2345Cylinder 10 Above Knock/Combustion Vibration Sensor Threshold
- P2343Cylinder 8 Above Knock/Combustion Vibration Sensor Threshold
- P2346Cylinder 11 Above Knock/Combustion Vibration Sensor Threshold
- P0324Knock/Combustion Vibration Control System Error
- P0325Knock/Combustion Vibration Sensor A Circuit
- P0309Cylinder 9 Misfire Detected
Sources
- en.wikipedia.org: V10 engine
- saabwisonline.com: dtc p0324 p0326 p0331 p06b6 or p06b7
- en.wikipedia.org: Engine knocking
- law.cornell.edu: 13 CCR 1968.2
Values and procedures vary by manufacturer. If it affects brakes, steering, fuel or high voltage, see a professional. Updated: 2026-11-04. How we build these pages.