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P0300: Random/Multiple Cylinder Misfire Detected

The engine is misfiring across more than one cylinder.

Can I Keep Driving with Code P0300?

Avoid driving long distances. Misfires damage the catalytic converter quickly.

What P0300 Means

P0300 means multiple cylinders are misfiring, with no single cylinder identified. Common causes include old spark plugs, weak coils, low fuel pressure, or vacuum leaks affecting all cylinders.

Common Causes

• Worn spark plugs — see repair cost
• Weak ignition coils
• Vacuum leak
• Low fuel pressure — see repair cost
• Dirty fuel injectors — see repair cost

Diagnostic Tips

• Always start with spark plugs if they have not been replaced recently.
• Each misfire damages the cat. A $1,500 cat is much more than a $150 plug job.
• Pull live misfire counts with a scan tool to narrow down which cylinders.

Frequently Asked Questions

Other Common Codes