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P0308

Cylinder 8 Misfire Detected

The engine is not burning fuel properly in cylinder 8. This can cause rough running, poor power, fuel smell, and damage to the catalytic converter if ignored.

Severity4/5 High
Can I drive?⚠ With caution

You may be able to drive a short distance, but continued driving can damage the catalytic converter and worsen the misfire. If the engine is shaking badly, flashing the check engine light, or lacking power, stop driving and diagnose it right away.

DIY
$20–$250
Shop
$150–$1,000
Difficulty
intermediate

What It Means

P0308 is set when the engine computer detects misfire events on cylinder 8. The misfire may be caused by ignition, fuel delivery, air leak, compression loss, or wiring problems affecting that specific cylinder. If the misfire is severe or persistent, unburned fuel can overheat and damage the catalytic converter.

Symptoms

Common Causes

1. Faulty spark plug in cylinder 8high
2. Bad ignition coil or coil boot on cylinder 8high
3. Fuel injector for cylinder 8 clogged, weak, or not firingmedium
4. Vacuum leak or intake manifold leak near cylinder 8medium
5. Worn engine compression issue such as bad valve, piston ring, or head gasket leakmedium
6. Damaged wiring, connector, or PCM control issue for cylinder 8 ignition/injector circuitlow
7. Incorrect fuel pressure or contaminated fuellow

Related Codes

FAQ

Is P0308 serious?

Yes. A misfire can damage the catalytic converter and may leave you stranded if the problem gets worse.

Can I keep driving with P0308?

Short trips may be possible if the engine runs reasonably well, but you should repair it soon. Do not keep driving if the check engine light is flashing or the engine runs very rough.

What usually fixes P0308?

The most common fix is replacing the spark plug or ignition coil for cylinder 8. If that does not solve it, the injector, wiring, vacuum leaks, or compression should be checked.

Can a bad fuel injector cause P0308?

Yes. If cylinder 8 is not getting the right amount of fuel, it can misfire and trigger this code.