P0300 🟠 Élevé ⚠️ Do not drive
Random/Multiple Cylinder Misfire Detected
The engine is misfiring across multiple cylinders with no specific pattern. A flashing check engine light means catalytic converter damage is occurring — stop driving immediately.
🚗 Common on: All makes and models
💷
Average repair cost
£15 — £450
🔍 Symptoms
- → Flashing check engine light (urgent!)
- → Rough idle / vibrations
- → Engine stuttering or hesitation
- → Hard starting
- → Loss of power
⚙️ Common Causes
- 1Worn spark plugs (most common cause)
- 2Faulty ignition coils
- 3Clogged or failing injectors
- 4Low compression (head gasket)
- 5Fuel pressure issue
🔧 Recommended Fixes
- 1Replace spark plugs (£15-60 for a set) — always start here
- 2Test and replace ignition coils (~£25-50 each)
- 3Clean or replace injectors
- 4Compression test each cylinder
- 5Check fuel pressure
🛒 Recommended Parts (Amazon UK)
NGK Spark plugs set~£15-45
View on Amazon UK →Ignition coil~£20-50 each
View on Amazon UK →Fuel injector cleaner~£8
View on Amazon UK →OBD2 scanner~£22
View on Amazon UK →Affiliate links — same price for you, we may earn a small commission.
Frequently Asked Questions
Can I clear this code without fixing it?
Yes, but it will return if the underlying issue isn't fixed. Clearing a code only tells you if the problem is permanent or intermittent.
Will this code fail an MOT?
Yes — this code will likely cause an MOT failure. Get it repaired before your test.