Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that the car's computer has noticed that cylinder number 6 in the engine isn't working right. It's like one of the pistons isn't firing properly, which can make the car run rough.
The engine control module (ECM) has detected that cylinder 6 is not firing correctly, which can cause a rough idle and poor engine performance.
The P0306 code indicates that the ECM has detected a misfire in cylinder 6. This misfire can be due to a variety of issues such as a faulty spark plug, ignition coil, fuel injector, or compression problems in that cylinder.
• Check Engine Light is on
• Rough idling
• Poor acceleration
• Increased emissions
• Engine stalling
• Faulty spark plug in cylinder 6
• Defective ignition coil
• Fuel injector issues
• Vacuum leaks
• Low compression in cylinder 6
ECM: Engine Control Module
Misfire: Failure of the fuel/air mixture in a cylinder to ignite properly
• Use an OBD-II scanner to confirm the P0306 code.
• Inspect the spark plug and ignition coil for cylinder 6.
• Check the fuel injector for proper operation.
• Perform a compression test on cylinder 6.
• Replace the spark plug in cylinder 6.
• Replace the ignition coil if faulty.
• 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
• Toyota Camry
• Regularly replace spark plugs.
• Perform routine engine maintenance.
• Use quality fuel.
Engine Performance
• Do not ignore the Check Engine Light.
• Have the vehicle inspected by a professional if unsure.
• Regular maintenance can prevent misfires.
Check with your vehicle's manufacturer for warranty coverage on ignition components.
Misfire codes like P0306 have been common in vehicles since the introduction of OBD-II systems in the mid-1990s.
Moderate – The vehicle may continue to run, but performance and fuel efficiency will be affected. Prolonged driving can cause damage.
Driving with a misfire can increase emissions and may not pass emissions testing in some areas.
• Engine at operating temperature
• Under load conditions
Cylinder 6 is typically located at the rear of the engine on the passenger side in a V6 or V8 engine configuration.
Q: Can I drive with a P0306 code?
A: It's not recommended to drive for long periods with a P0306 code as it can cause further engine damage.
Q: How do I know which cylinder is number 6?
A: Refer to the vehicle's service manual for the cylinder numbering order.
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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.