All codes › P0300
P0300: Random/Multiple Cylinder Misfire Detected
What it means
Misfires are happening in several cylinders or moving around randomly. That points to something shared rather than one bad coil.
Severity: High Multiple-cylinder misfire; a flashing light means stop driving hard.
Common causes
- Vacuum leak
- Low fuel pressure
- Worn spark plugs (all)
- Faulty MAF
- Bad crank sensor signal
Most common causes first. Exact causes vary by make, model and engine.
Can I fix it myself?
Sometimes DIY. Look for shared causes: vacuum leaks, old plugs, fuel pressure.
Repair cost
SEEDED ESTIMATE Roughly $120–$520
Most likely repair: spark plug (each). Diagnosis fees, taxes and other causes are not included.
| Line | Low | High | Basis |
|---|---|---|---|
| Spark plug (each) ×6 | $18 | $120 | Typical listed retail range, source |
| Labor 1–2.5 hr | $100 | $400 | $100–$160/hr, shop survey |
⚠️ This is an editorial placeholder range for this type of repair. It is not based on real invoices or licensed pricing data yet. Real ranges will appear here once enough reader invoices for P0300 are verified.
Verified reader invoices for P0300: 0. Share your repair bill to help build real costs.
Tools that can read P0300
- ScanFixAI: Pro $29.99/mo or $249.99/yr
- OBDAI: Annual PRO bundle $299
- BlueDriver Pro Next-Gen: $119.95 list ($99.95 sale seen)
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