P0306 on Mazda: How to Diagnose & Fix
Cylinder 6 Misfire Detected
1 Mazda model · 1 documented issue · $80-$300 repair
P0306 on Mazda by model: symptoms, diagnosis and fix
Ignition coil-on-plug coils fail causing misfires. Ford 3.0L Duratec V6 coils are prone to cracking and arcing. Usually fails one at a time.
Common Symptoms
- Engine misfire
- Check engine light flashing
- Rough idle
- Loss of power
- Poor fuel economy
How to Fix
Replace failed ignition coil. Replace all 6 spark plugs when replacing any coil. Consider replacing all coils proactively if one fails.
What you need to fix it
Only diagnosis- and fitment-reviewed repair parts are linked here.
- Genuine Mazda AJ09-18-100 direct ignition coilOEMMazda AJ09-18-100
Individual OEM coil replacement after a 3.0L cylinder-specific ignition failure is confirmed Fitment/availability: The inspected direct OEM dealer page identifies AJ09-18-100 and its Tribute fitment through 2001-2010. Confirm VIN/engine …
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P0306 code reference
General diagnostic-code context. The code alone does not confirm a cause for your vehicle; use the applicable issue card and its sources.
Frequently asked questions
What does P0306 mean on a Mazda?
P0306 stands for "Cylinder 6 Misfire Detected." This code means the engine computer detected a misfire on cylinder 6 — that cylinder isn't burning its fuel-air mixture properly. The computer senses misfires by watching for tiny variations in crankshaft speed each time a cylinder should fire, and when cylinder 6 repeatedly fails to contribute, this code sets. You may feel a shake or stumble, especially at idle or under load, along with reduced power and possibly a flashing check-engine light, which signals a misfire severe enough to damage the catalytic converter. A misfire comes down to a problem with spark, fuel, or compression in that cylinder. On Mazda it is documented across 1 model: Tribute.
What are the most common causes of P0306?
The most common causes of P0306 are: Worn or fouled spark plug on cylinder 6, Failed ignition coil for cylinder 6, Clogged, leaking, or failed fuel injector, Vacuum or intake air leak affecting that cylinder, Low compression (worn rings, burnt valve, head gasket), Damaged plug wire or coil connector, Carbon buildup or worn valvetrain components. The specific cause varies by vehicle.
How much does it cost to fix P0306 on a Mazda?
Published repair estimates on Mazda range from $80 to $300 depending on the model and root cause. If an issue mentions a recall or campaign, check your VIN with the manufacturer or NHTSA and confirm eligibility and coverage with a dealer.
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Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.