P0307: Cylinder 7 Misfire Detected
Can you still drive? Not recommended if the check engine light is flashing. Unburned fuel from the misfiring cylinder can destroy the catalytic converter.
What Does P0307 Mean?
Code P0307 indicates that the ECM has detected repeated misfires on cylinder 7. Since cylinder 7 is only present on V8 or larger engines, this code is specific to vehicles with those configurations. Misfires can be caused by ignition, fuel, or compression issues.
Need to read your codes?
An OBD-II scanner lets you read and clear diagnostic trouble codes from your vehicle's computer. Most scanners work with any car made after 1996.
Browse OBD-II Scanners on AmazonCommon Causes
- Worn spark plug on cylinder 7
- Faulty ignition coil on cylinder 7
- Clogged fuel injector
- Low compression due to valve or piston issue
- Intake manifold gasket leak
Symptoms
- Check engine light flashing
- Rough idle
- Loss of power
- Engine vibration
- Increased exhaust emissions
Diagnostic Steps
- 1Inspect spark plug on cylinder 7 for wear or fouling
- 2Swap ignition coil with another cylinder to test
- 3Test fuel injector operation using a noid light
- 4Perform compression test on cylinder 7
- 5Check for vacuum leaks near cylinder 7 intake port
Recommended Parts & Tools
ignition coil
spark plug set
fuel injector cleaner
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $50 - $1500 |
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Chat with AI About P0307Commonly Affected Vehicles
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Frequently Asked Questions
Why does only cylinder 7 misfire?
Cylinder-specific misfires usually point to a component failure on that specific cylinder, such as a bad coil, fouled spark plug, or clogged injector.
Can I swap coils to diagnose P0307?
Yes, swapping the cylinder 7 coil with another cylinder is a quick diagnostic. If the misfire moves to the new cylinder, the coil is faulty.
Is P0307 an expensive repair?
It depends on the cause. A spark plug or coil is under $100, but low compression may indicate a valve or piston issue costing $1,000 or more.
Community Fix Reports
Community reports are user-submitted and not verified by Auto AI Buddy. Results may vary.
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