P0300

Random/Multiple Cylinder Misfire Detected

Q: What does fault code P0300 mean?

Random/Multiple Cylinder Misfire Detected. The ECM detected misfires occurring randomly across multiple cylinders. A flashing check engine light means catalytic converter damage risk — reduce load immediately.

Q: What are the symptoms of P0300?

Check engine light (steady or flashing); Rough idle; Power loss; Vibration; Higher fuel use

Q: What are the possible causes of P0300?

Worn spark plugs; Faulty ignition coils; Clogged or leaking injectors; Vacuum leaks; Low fuel pressure; Faulty CKP/CMP sensor; Bad fuel; Low compression

Q: How to fix P0300?

Replace plugs if worn; Swap coils to isolate bad ones; Smoke-test for vacuum leaks; Check fuel pressure; Scan for related P0301–P0308; If MIL flashing, ease off throttle

Severity: High Ignition System Generic OBD-II Code Est. Repair: $150 - $600

High severity. Avoid long drives and get diagnosed as soon as possible. Flashing check engine light = stop driving if safe.

What Does P0300 Mean?

The ECM detected misfires occurring randomly across multiple cylinders. A flashing check engine light means catalytic converter damage risk — reduce load immediately.

Common Symptoms

Check engine light (steady or flashing)

Rough idle

Power loss

Vibration

Higher fuel use

Possible Causes

Worn spark plugs

Faulty ignition coils

Clogged or leaking injectors

Vacuum leaks

Low fuel pressure

Faulty CKP/CMP sensor

Bad fuel

Low compression

How to Fix P0300 – Repair Guide

Replace plugs if worn

Swap coils to isolate bad ones

Smoke-test for vacuum leaks

Check fuel pressure

Scan for related P0301–P0308

If MIL flashing, ease off throttle

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Disclaimer: Information is for educational reference only and does not replace professional diagnosis. Actual causes and costs vary by vehicle make, model, year and condition. Always verify with a qualified technician.