P0307
High SeverityCylinder 7 Misfire Detected
Ignition System
P0307 — Instant Answer
Cylinder 7 Misfire Detected
Severity: HIGH SEVERITY
Meaning: Cylinder 7 is misfiring. Only on V8 engines.
Safe to drive? NO if CEL is flashing. YES with caution if solid, but repair this week.
Estimated repair cost: $20 - $500
Most common causes:
- 1. Bad spark plug (35-45% of cases)
- 2. Faulty coil (35-45% of cases)
- 3. Bad injector (10-25% of cases)
Common Causes
How to Diagnose P0307
- 1Swap plug/coil
- 2Check injector
- 3Compression test
OEM Procedures for P0307
P0307 affects the Spark Plug. Found 116 OEM service manual procedures.
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
1969-73 PEUGEOT 504 4 Cylinder - Spark Plug Tube Replacement
Showing 8 of 116 procedures
OEM Diagnostic Flowchart
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Related Resources
Repair guides, symptom pages, and wiring diagrams related to P0307.
Exact Repair Workflows
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Open the exact repair flow most commonly associated with P0307 on this vehicle.
Open the exact repair flow most commonly associated with P0307 on this vehicle.
Open the exact repair flow most commonly associated with P0307 on this vehicle.
Open the exact repair flow most commonly associated with P0307 on this vehicle.
Open the exact repair flow most commonly associated with P0307 on this vehicle.
Related Symptoms
Browse →Rough idle often traces back to ignition, air metering, vacuum leaks, or timing-related faults before it becomes a full misfire complaint.
A check-engine light is a graph entry point into code pages, symptom-specific diagnosis, and the exact repair categories most often associated with those failures.
Exact Vehicle Hubs
Browse →Open the exact vehicle hub for a repair workflow commonly associated with P0307.
Open the exact vehicle hub for a repair workflow commonly associated with P0307.
Open the exact vehicle hub for a repair workflow commonly associated with P0307.
Open the exact vehicle hub for a repair workflow commonly associated with P0307.
Open the exact vehicle hub for a repair workflow commonly associated with P0307.
Open the exact vehicle hub for a repair workflow commonly associated with P0307.
Related Codes
The engine is misfiring across multiple cylinders. This is often caused by something that affects all cylinders — spark plugs, fuel quality, vacuum leak, or low compression.
Cylinder 6 is misfiring. Only on 6+ cylinder engines.
Cylinder 8 is misfiring. Only on V8 engines.
Frequently Asked Questions
- What V8 engines have cylinder 7 issues?
- GM V8s with AFM/DFM (cylinder deactivation) sometimes have specific cylinder issues. Check for AFM-related problems.
- Is P0307 an emergency?
- If the check engine light flashes, yes — pull over. Steady light means you can drive to a shop.
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Author & Review
Written by AllOEMManuals Editorial Team. Reviewed by ASE-certified technicians and updated with factory-reference checks for fitment-sensitive steps.
This guide was drafted with AI assistance and reviewed for accuracy by a human editor.
Last updated: 2026-05-07