P0300 on Hyundai: Random or Multiple Cylinder Misfire Detected
Severity: 3 of 4
Park it if the check engine light is flashing or the engine is shaking. A flashing light means misfires severe enough to damage the catalytic converter and in extreme cases cause an exhaust fire. If the light is steady and the misfire is mild, drive only as far as needed to get it diagnosed, gently and without heavy loads.
Estimate range covers the repairs listed below; see the cost breakdown. A flashing check engine light, a hot temperature gauge, or brakes that feel different mean stop driving and get help.
What P0300 usually means on a Hyundai
Some Hyundai engines are covered by recalls and extended warranties for connecting rod bearing failure. Knocking with misfires on those engines deserves prompt attention. Knocking or oil consumption with misfires deserves prompt attention.
Most likely causes on Hyundai vehicles
- Spark plugs
- Ignition coils
- Engine mechanical issues covered by recall
- Vacuum leak
Order reflects cost and likelihood in general; your vehicle may differ. Confirm with testing before buying parts.
Hyundai specific tips
- Check NHTSA recalls with your VIN.
- Listen for knocking; stop driving if it gets worse.
Estimated repair cost
This is an estimate, built from typical parts price ranges plus labor hours times an assumed shop rate of $110 to $190 per hour. Actual prices vary by vehicle, region, and shop. Diagnosis fees are often extra.
| Repair | Parts | Labor | Estimate (low / high) |
|---|---|---|---|
| Spark plugs, full set | $20 to $120 | 0.5 to 2.5 h | $20 + 0.5 × $110 = $75 $120 + 2.5 × $190 = $595 |
| Vacuum hose or intake gasket | $10 to $120 | 0.5 to 2.5 h | $10 + 0.5 × $110 = $65 $120 + 2.5 × $190 = $595 |
| Ignition coil, one | $30 to $150 | 0.2 to 1.0 h | $30 + 0.2 × $110 = $52 $150 + 1.0 × $190 = $340 |
| Fuel pump | $120 to $600 | 1.5 to 3.5 h | $120 + 1.5 × $110 = $285 $600 + 3.5 × $190 = $1,265 |
Costs are generic for this code; parts and labor on some Hyundai models may run higher.
Watch a repair video
How to Fix a Random Engine Misfire in Your Car (Code P0300) (Scotty Kilmer). Third-party video, loads from YouTube (privacy-enhanced mode) only when you press play. Procedures vary by vehicle. Search YouTube for “P0300 Hyundai fix” videos.
Repair manuals
Step-by-step service manuals for Hyundai with torque specs and wiring diagrams:
Haynes manuals for Hyundai Chilton manuals
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Check Hyundai recalls
Enter your VIN at the NHTSA recall lookup before paying for repairs.
FAQ
Could my Hyundai misfire be covered?
Possibly. Check recalls and warranty extensions.
Read the full P0300 guide or more Hyundai check engine notes.