AutoSense AI Knowledge Base
P0306 Code: Cylinder 6 Misfire Detected
P0306 means cylinder 6 is not completing combustion consistently. Learn the common symptoms, causes, severity, and typical repair costs.
The P0306 code means cylinder 6 is not completing combustion consistently. It is stored when the engine computer sees a signal or operating condition outside the expected range.
Ignition and misfire codes mean the engine computer detected incomplete combustion or unreliable timing information. The right fix depends on live data, freeze-frame information, service history, and whether other codes are present.
Symptoms
- Check engine light
- Rough idle
- Shaking under acceleration
- Loss of power
- Poor fuel economy
- Fuel smell from exhaust
Common Causes
- Worn spark plug
- Failing ignition coil
- Clogged or leaking fuel injector
- Vacuum leak
- Low compression
- Wiring or connector problem
Severity
High if the check engine light is flashing. Active misfires can damage the catalytic converter quickly.
Typical Repair Costs
$100 to $2,000+
- The lower end usually covers inspection, cleaning, wiring repair, or a simple sensor replacement.
- The higher end applies when parts are hard to access or when the code is caused by a larger mechanical, emissions, or transmission problem.
- Always diagnose before replacing parts, because one code can be triggered by several related systems.
Frequently Asked Questions
What does code P0306 mean?
P0306 means cylinder 6 is not completing combustion consistently. The exact cause should be confirmed with diagnostic data before replacing parts.
Can I drive with a P0306 code?
It depends on symptoms. If the car runs poorly, overheats, stalls, shifts harshly, or the check engine light flashes, limit driving and diagnose it promptly.
What is the most common fix for P0306?
Common fixes include addressing worn spark plug, failing ignition coil, clogged or leaking fuel injector, but testing is needed to avoid replacing the wrong part.
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Engine Misfire Symptoms, Causes, and Repair Cost
A misfire happens when one or more cylinders fail to burn fuel correctly, causing shaking, power loss, and potential converter damage.
Rough Idle: Symptoms, Causes, and Repair Cost
A rough idle can come from air, fuel, ignition, sensor, or mechanical issues.
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