P0309: Cylinder #9 Misfire Detected
Is your scanner showing P0309?
No worries. We'll show you what it means and how to deal with it.
P0309: Cylinder #9 Misfire DetectedOVERVIEW
What Does The P0309 Code Mean?
A P0309 code means that the the car’s computer has detected that one of the engine’s cylinders is not firing properly. In this case it’s cylinder #9.
What Are The Symptoms Of The P0309 Code?
Symptoms may include:
- the engine may be harder to start
- the engine may stumble / stumble, and/or hesitate
- other symptoms may also be present
What Are The Potential Causes Of The P0309 Code?
A code P0309 may mean that one or more of the following has happened:
- Faulty spark plug or wire
- Faulty coil (pack)
- Faulty oxygen sensor(s)
- Faulty fuel injector
- Burned exhaust valve
- Faulty catalytic converter(s)
- Running out of fuel
- Poor compression
- Defective computer
How Can You Fix The P0309 Code?
If there are no symptoms, the simplest thing to do is to reset the code and see if it comes back.
If there are symptoms such as the engine is stumbling or hesitating, check all wiring and connectors that lead to the cylinders (i.e. spark plugs). Depending on how long the ignition components have been in the car, it may be a good idea to replace them as part of your regular maintenance schedule. I would suggest spark plugs, spark plug wires, distributor cap, and rotor (if applicable). Otherwise, check the coils (a.k.a. coil packs). In some cases, the catalytic converter has gone bad. If you smell rotten eggs in the exhaust, your cat converter needs to be replaced. I’ve also heard in other cases the problems were faulty fuel injectors.
Below are some recommended auto parts to help you address the trouble code affecting your vehicle and get it running smoothly again:
Note: During the purchasing process, please check carefully whether the part you want to buy fits your car!
P0309: Cylinder #9 Misfire, OBD-Codes.