What causes Subaru to misfire?
Common causes are low fuel pressure and faulty fuel injectors. If the fuel injector is the problem, it can often simply be replaced; it’s also a good idea to check the fuel pump. Occasionally, a mechanical issue may cause an engine misfire–though this is relatively rare.
What causes a misfire on cylinder 3?
P0303 indicates that cylinder number 3 is experiencing misfires. A misfire occurs when an insufficient amount of fuel is burning in a cylinder. A misfire from one or more cylinders can be caused by many reasons from a faulty ignition system, fuel system, or internal engine failure.
How do I fix code po303?
What repairs can fix the P0303 code?
- Spark plug replacement for all cylinders.
- Replacing the cap & rotor, coil pack, or spark plug wiring as necessary.
- Intake air leaks repaired.
- Repairing fuel issues.
- Mechanical engine issues fixed.
How do you fix a misfire in a cylinder?
Inspect the spark plugs for signs of damage. Use a spark plug socket to remove the plug so you can get a good look at it. The damage you see will help you determine the cause of the misfire. If the spark plug is just old, replacing it may solve the problem. Make sure to replace and properly gap new spark plugs.
How can you tell if you have a bad coil pack?
Common Symptoms of a Faulty Coil Pack
- A rough idle.
- An unexplainably louder-than-usual engine.
- A noticeable lack of power.
- A significant drop in RPMs while accelerating for no apparent reason.
- A blinking or intermittently activating check engine light.
- An active gas warning light when the vehicle has plenty of gasoline.
Is it expensive to fix a cylinder misfire?
It’s hard to predict an exact cost for repairing a misfiring engine. For instance, a problem with a bad on plug ignition coil might end up costing you $300 to $400 on a newer model, four-cylinder engine. The coil will have to be replaced as well as all of the spark plugs.