2016-2021 Honda Civic Trouble Code P0308: Cylinder 8 Misfire Detected
If your 2016-2021 Honda Civic (1.5L VTEC Turbo (L15B7), 2.0L i-VTEC NA (K20C2)) is triggering code P0308, accompanied by V8 engine rumble unevenness, deep exhaust vibration, hesitation on highway pass, inspect the primary mechanical failure points below. You can record your live engine sound to verify symptoms with Carithm's free neural acoustic engine.
🎙️ Free Honda Civic Engine Sound Diagnoser
Neural Engine ReadyTip: Hold your smartphone microphone 12–18 inches above the valve cover or near the tailpipe while recording.
Vehicle-Specific Causes for 2016-2021 Honda Civic
On the 10th Gen Global Compact Architecture equipped with the 1.5L VTEC Turbo (L15B7), 2.0L i-VTEC NA (K20C2), our automotive repair database indicates the following primary root causes for P0308:
Documented Failure Pattern:
1.5L Turbo fuel dilution in engine oil thinning viscosity, or premature spark plug carbon tracking under high boost.
General Root Causes: Cylinder 8 rear firewall heat-soak coil failure, intake gasket leak, or AFM lifter collapse (Chevy 5.3/6.2L).
Quick DIY Verification Steps
Before scheduling an expensive workshop appointment, perform these basic diagnostic checks:
- Acoustic Isolation: Does the engine make V8 engine rumble unevenness, deep exhaust vibration, hesitation on highway pass? Note if the frequency doubles with engine RPM or remains constant.
- Targeted Physical Check: Check spark plug electrode wear and test compression pressure on rear cylinder 8 against bank 1 spec.
- AI Audio Cross-Check: Use the free tool above to analyze your engine audio recording for mechanical harmonic abnormalities.
Estimated Repair Cost Benchmarks
Typical repair costs for resolving P0308 on a 2016-2021 Honda Civic at certified independent repair shops:
| Diagnostic & Repair Tier | Estimated Parts | Estimated Labor |
|---|---|---|
| Minor (Sensor clean, hose, wiring repair) | $38 – $57 | $90 – $125 |
| Moderate (OEM Sensor, injector, coil pack) | $60 – $106 | $135 – $216 |
| Comprehensive (Timing, manifold, internal) | $190 – $371+ | $388 – $648+ |
*Cost estimates based on national US independent mechanic labor rates ($110–$160/hr). Dealership pricing may be 30–50% higher.
Frequently Asked Questions
What does code P0308 mean on a 2016-2021 Honda Civic?
Code P0308 indicates Cylinder 8 Misfire Detected. On the 2016-2021 Honda Civic (1.5L VTEC Turbo (L15B7), 2.0L i-VTEC NA (K20C2)), this fault is commonly triggered by: 1.5L Turbo fuel dilution in engine oil thinning viscosity, or premature spark plug carbon tracking under high boost.
Is it safe to drive my 2016-2021 Honda Civic with code P0308?
Severity Assessment: 🔴 High Risk. If your check engine light is flashing or accompanied by rough running, hesitation, or unusual mechanical knocking, discontinue driving immediately to avoid catalytic converter burnout or valvetrain destruction.
What engine sounds are associated with P0308 on 2016-2021 Honda Civic?
Drivers frequently report: V8 engine rumble unevenness, deep exhaust vibration, hesitation on highway pass. Listening closely to your engine audio helps verify whether the root failure is an electrical sensor glitch, vacuum line leak, or mechanical valvetrain wear.
How much does it cost to fix code P0308 on a 2016-2021 Honda Civic?
Estimated repair costs for the 2016-2021 Honda Civic typically range from – for replacement parts and – for professional labor at certified independent repair shops.