Random/Multiple Cylinder Misfire Detected
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.
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
Appears alongside · share of P0300 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.
P0300 by make
Based on commonly reported failure patterns across owner and repair communities, not on our scan data.
BMW
On BMWs, aging plugs and ignition coils are the usual cause, particularly on turbocharged models. A fuel delivery or vacuum leak problem can also contribute.
Chevrolet
On Chevrolet V8 trucks and SUVs with Active Fuel Management, worn lifters are a commonly reported cause, along with plugs, coils and vacuum leaks. A flashing light means get it checked soon.
Dodge
On Dodge vehicles with the 5.7L Hemi, worn lifters and spark plugs are commonly reported causes of random misfires. A ticking sound with this code deserves a check soon.
Ford
Commonly reported on Ford trucks and SUVs from worn plugs and coils, such as on the 5.4L Triton, and from vacuum leaks. A flashing check engine light means get it checked soon.
GMC
On GMC V8 trucks and SUVs with Active Fuel Management, worn lifters are a commonly reported cause, along with plugs, coils and vacuum leaks. A flashing light means get it checked soon.
Honda
On Honda V6 models with cylinder deactivation, fouled plugs and oil in the plug wells can cause random misfires. Check the plugs and the valve cover gaskets.
Hyundai
On Hyundai models with the 2.4L four-cylinder, random misfires can be a sign of engine wear as well as plugs and coils. Get it checked soon if there is knocking or oil use.
Jeep
On Jeeps with the 5.7L Hemi or 3.6L V6, plugs, coils and lifters are the usual places to start. A flashing check engine light means get it checked soon.
Kia
On Kia models with the 2.4L four-cylinder, random misfires can be a sign of engine wear as well as plugs and coils. Get it checked soon if there is knocking or oil use.
Nissan
On Nissans, worn plugs and coils are the usual causes of random misfires, particularly on V6 models. A vacuum leak is another possibility.
Ram
On Ram trucks with the 5.7L Hemi, worn lifters and spark plugs are commonly reported causes of random misfires. A ticking sound with this code deserves a check soon.
Subaru
On Subarus, worn plugs, coils and vacuum leaks are the first things to look at. On older 2.5L boxer engines, a leaking head gasket is another commonly reported cause.
Toyota
On Toyotas, worn spark plugs, failing coils or a vacuum leak are the usual causes of random misfires. If the plugs are fresh, look at the coils and intake leaks next.
Volkswagen
On VW and Audi turbo engines, worn plugs and failing coils are the most common reasons for random misfires. They are often cheap to replace as a set.
FAQ
Quick answers
Is it safe to drive with P0300?+
Can I just clear the code?+
Related codes
Read more about this code
Read & clear P0300 yourself
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