TorqueMech OBD Code Guide
P0308 - Cylinder 8 Misfire Detected
The ECM detected a misfire on cylinder 8.
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Common Next Steps
Turn the code into the next check.
Inspect ignition coils
Check coil boots, carbon tracking, and whether the miss follows a swap.
Check spark plugs
Inspect gap, fouling, wear, oil, coolant, and plug-well condition.
Verify injector operation
Move to injector balance, pulse, or leak-down checks if the misfire stays.
Check compression if needed
Use compression or leak-down testing when spark and fuel checks do not move the fault.
Related Inspection
Code Overview
The ECM detected a misfire on cylinder 8.
Common Causes
- Worn or fouled spark plug on cylinder 8
- Weak ignition coil, boot, or plug wire for cylinder 8
- Fuel injector issue on cylinder 8
- Vacuum leak affecting the cylinder 8 runner
- Low compression or valve sealing problem on cylinder 8
Symptoms
- Rough idle or uneven engine note
- Weak pull or stumble during acceleration
- Fuel smell or flashing MIL if the misfire gets severe
Diagnostic Steps
- Swap the coil or plug with another cylinder and see whether the misfire follows
- Inspect the cylinder 8 spark plug, boot, and plug well for wear or oil intrusion
- Check injector operation and connector condition on cylinder 8
- Perform compression or leak-down testing if the misfire stays on the same hole
Repair Difficulty
Moderate
General difficulty estimate for the most common repair path.
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Next Steps
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