Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected that cylinder number 8 in the engine is not working properly. It's like one of the cylinders isn't firing like it should, which can make the car run rough or lose power.
A misfire in cylinder 8 means that the combustion process in that cylinder is not happening as it should. This can be due to a lack of fuel, spark, or air.
The P0308 code indicates that the engine control module (ECM) has detected a misfire in cylinder number 8. This can be caused by issues such as a faulty spark plug, ignition coil, fuel injector, or a problem with the engine's mechanical components.
• Check Engine Light is on
• Rough engine idle
• Loss of power
• Increased fuel consumption
• Engine hesitation
• Faulty spark plug in cylinder 8
• Defective ignition coil
• Fuel injector malfunction
• Vacuum leak
• Low engine compression
ECM: Engine Control Module - the computer that controls the engine's operation.
Misfire: A failure of the air/fuel mixture in the cylinder to ignite at the proper time.
• Use an OBD-II scanner to confirm the P0308 code.
• Inspect the spark plug and ignition coil for cylinder 8.
• Check the fuel injector for proper operation.
• Perform a compression test on cylinder 8.
• Replace the spark plug in cylinder 8.
• Replace the ignition coil for cylinder 8.
• Clean or replace the fuel injector.
• Repair any vacuum leaks.
• OBD-II scanner
• Spark plug socket
• Multimeter
• Compression tester
$150 - $500
Moderate
• Ford F-150
• Chevrolet Silverado
• Dodge Ram
• Regularly replace spark plugs and ignition components.
• Use high-quality fuel.
• Perform regular engine maintenance.
Engine Performance
• Do not ignore the Check Engine Light.
• Have your vehicle inspected by a professional if you're unsure.
• Regular maintenance can prevent misfire issues.
Check with your vehicle manufacturer for warranty coverage on ignition components.
Misfire codes like P0308 have been common since the introduction of OBD-II systems in the mid-1990s. They are used to help diagnose engine performance issues.
Moderate – While the vehicle may still be drivable, ignoring the issue can lead to more severe engine damage.
Driving with a misfire can lead to increased emissions and potential engine damage. It's important to address the issue promptly.
• Engine at operating temperature
• Vehicle in a safe, stationary position
Cylinder 8 is typically located at the rear of the engine on the passenger side, but this can vary by vehicle make and model.
Q: Can I drive with a P0308 code?
A: While you might be able to drive with this code, it's not recommended as it can cause further damage to the engine.
Q: How can I prevent a cylinder misfire?
A: Regular maintenance, including changing spark plugs and ignition components, can help prevent misfires.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.