P0300

Random/Multiple Cylinder Misfire Detected

Ignition / misfire Generic OBD-II High

What it means

P0300 means the engine is misfiring on random or multiple cylinders — fuel isn't burning properly, so the engine runs rough and loses power. It's one of the more serious common codes: sustained misfires can overheat and destroy the catalytic converter.

High

Can I keep driving? Not for long — a flashing check-engine light means an active misfire; drive as little as possible until fixed to avoid converter damage.

Real-world scan data

Seen in

18,271

scans in the past year

Found in

2.9%

of scans

5.2%

of scans that found faults

Appears alongside · share of P0300 scans

P0301in 50.7% of scans

P0303in 49.9% of scans

P0302in 49.9% of scans

Figures reflect only diagnostic scans recorded through our own apps and tools. Cars are typically scanned because a symptom or warning light prompted it, so these counts describe our scan records — not the incidence of faults in any model, and not the quality, reliability, or safety of any vehicle. No comparison between manufacturers or models is implied. All trademarks belong to their respective owners; no affiliation or endorsement is implied.

Common symptoms

What you'll notice

Check-engine light on (often flashing during an active misfire)
Rough idle, shaking, or stalling
Reduced power and hesitation on acceleration
Increased fuel consumption

Common causes

Most likely first

Worn spark plugs or failing ignition coilsLikely
Clogged or leaking fuel injectors / low fuel pressureCommon
Vacuum leak in the intakeCommon
Failing sensors (coolant temp, MAF, O2)Less often
Mechanical — low compression or valvetrain wearLess often

How to diagnose & fix

Work through it in order

Read freeze-frame data and check for cylinder-specific codes (P0301-P0308) to pinpoint the miss.
Inspect and replace worn spark plugs and coils first — the most common cause.
Check fuel delivery: injectors, fuel pressure, and filter.
Test for vacuum leaks around the intake.
If it persists, run a compression test for mechanical causes. Clear and re-test.

FAQ

Quick answers

Is it safe to drive with P0300?+

No — especially with a flashing light. Active misfires can quickly damage the catalytic converter.

Can I just clear the code?+

You can, but it returns within a few drive cycles until the misfire cause is repaired.