P0308 on Honda
Cylinder 8 Misfire Detected
P0308 on Honda vehicles indicates cylinder 8 misfire detected. Au7o has documented this code across 1 Honda model — most commonly on Fit. P0308 means the engine computer detected a misfire on cylinder number 8 — that cylinder is failing to combust properly or at the correct time. The PCM identifies it by monitoring crankshaft speed variations as cylinder 8 fires. Misfires waste fuel, increase emissions, and can overheat and damage the catalytic converter, so a hard misfire may cause a flashing check engine light. Typical symptoms include rough idle, vibration, hesitation, and reduced power. Typical repair costs on Honda range from $80 to $400, depending on the specific model and root cause.
Common Causes of P0308
- •Worn, fouled, or incorrectly gapped spark plug on cylinder 8
- •Failed ignition coil or coil-on-plug for cylinder 8
- •Faulty, clogged, or leaking fuel injector
- •Vacuum or intake air leak affecting that cylinder
- •Low compression (worn rings, burnt/leaking valve, head gasket)
- •Damaged spark plug wire or boot (on applicable engines)
- •Carbon buildup or sticking valve
P0308 on Honda by Model
Honda Fit(2 issues)
- Spark Plug Premature Failure2007-2020
Original equipment spark plugs fail prematurely across all Honda Fit generations, sometimes before 30,000 miles. Original iridium plugs don't hold up well in the L15A/L15B engines. FitFreak forum consensus: replace every 20,000-25,000 miles instead of Honda's recommended 30,000 miles. NGK Laser Platinum plugs are the consensus #1 choice among Fit owners. Improper spark plug gap or torque causes premature failure.
- Ignition Coil Failure2007-2020
Ignition coil packs can fail causing engine misfires. Usually one coil fails at a time. Engine misfire, rough idle, check engine light with misfire codes. Bosch ($50-80 each) or Denso ($60-90 each) replacement coils recommended on FitFreak. Replace all four at once ($200-300) to prevent future failures and repeated labor costs. DIY installation very easy (bolt on, connector plug) - saves $100-200 in shop labor.
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View P0308 across all makes →Frequently Asked Questions
What does P0308 mean on Honda?▼
P0308 stands for "Cylinder 8 Misfire Detected." P0308 means the engine computer detected a misfire on cylinder number 8 — that cylinder is failing to combust properly or at the correct time. The PCM identifies it by monitoring crankshaft speed variations as cylinder 8 fires. Misfires waste fuel, increase emissions, and can overheat and damage the catalytic converter, so a hard misfire may cause a flashing check engine light. Typical symptoms include rough idle, vibration, hesitation, and reduced power. On Honda specifically, this code is documented across 1 model.
What causes P0308 on Honda vehicles?▼
Common causes on Honda: Worn, fouled, or incorrectly gapped spark plug on cylinder 8, Failed ignition coil or coil-on-plug for cylinder 8, Faulty, clogged, or leaking fuel injector, Vacuum or intake air leak affecting that cylinder, Low compression (worn rings, burnt/leaking valve, head gasket). Specific causes vary by model and year — see the per-model sections below.
How much does it cost to fix P0308 on a Honda?▼
Repair costs on Honda range from $80 to $400, depending on the specific model and root cause.
Which Honda models have P0308 documented?▼
Au7o has documented P0308 on 1 Honda model: Fit.