P0308: Cylinder 8 Misfire Detected
Can you still drive? Not recommended when the check engine light is flashing. Continued misfires can cause catalytic converter failure, a very expensive repair.
What Does P0308 Mean?
Code P0308 means the ECM has detected consistent misfires on cylinder 8. As the last cylinder in a V8 engine, cylinder 8 can sometimes be more susceptible to heat-related issues due to its position. Ignition and fuel delivery problems are the most common causes.
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
- Failed ignition coil on cylinder 8
- Worn or fouled spark plug
- Clogged fuel injector
- Low compression
- Vacuum leak at intake manifold
Symptoms
- Check engine light flashing
- Rough idle
- Engine shaking
- Reduced power
- Exhaust popping or backfiring
Diagnostic Steps
- 1Remove and inspect cylinder 8 spark plug
- 2Swap ignition coil with a known good cylinder
- 3Test fuel injector with a noid light or scan tool
- 4Perform compression and leak-down test on cylinder 8
- 5Check intake manifold gasket for leaks near cylinder 8
Recommended Parts & Tools
ignition coil
spark plug set
compression tester
Estimated Repair Cost
| Type | Estimated Cost |
|---|---|
| Total Repair Cost Range | $50 - $1500 |
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Chat with AI About P0308Commonly Affected Vehicles
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Frequently Asked Questions
Is cylinder 8 harder to access?
On some V8 engines, cylinder 8 is at the rear of the engine bay, making spark plug and coil access more difficult. Budget extra time for the repair.
Can a misfire damage my engine?
A sustained misfire can wash oil from cylinder walls, damage the catalytic converter with unburned fuel, and in severe cases crack exhaust manifolds.
Community Fix Reports
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