P0300: Random/Multiple Cylinder Misfire Detected
Key takeaways
- P0300 means the engine is misfiring on more than one cylinder, or the misses move around, so the computer can't name a single cylinder.
- With a steady light and a car that runs mostly normally, keep it to short, gentle trips to get it fixed; a flashing light means stop driving and tow it.
- Because the cause is shared by several cylinders, look first at worn spark plugs, vacuum leaks and fuel delivery rather than one coil.
- Misfires dump unburned fuel into the exhaust, which can ruin a $1,000 to $2,500 catalytic converter if ignored.
- 448 owner complaints filed with NHTSA mention P0300, led by the Ford Escape with 35, most of them 2017 models.
What P0300 means
Your engine is misfiring, and the misses are spread across more than one cylinder or jumping around, so the computer can’t blame a single cylinder. Scanners call it “Random/Multiple Cylinder Misfire Detected.” The computer watches the crankshaft speed through the crankshaft position sensor: every cylinder that fires gives the crank a small push, and a cylinder that doesn’t fire lets it slow for an instant. When those slowdowns add up past a set rate and don’t stay on one cylinder, it sets P0300.
If the misfire sits on one cylinder, you get a numbered code instead: P0301 for cylinder 1, P0302 for cylinder 2, and so on. Many cars store P0300 alongside one or two of those.
Is it safe to drive?
Short, gentle trips only. If the light is steady and the engine runs close to normal, drive it to a shop or home with light throttle and no highway runs. Every misfire sends unburned fuel into the exhaust, where it burns inside the catalytic converter and overheats it.
If the check engine light is flashing, stop. OBD II rules make the light blink when misfire is bad enough to damage the converter. Pull over when it’s safe, shut the engine off and get a tow; our flashing check engine light guide explains what to do in the next five minutes. The same goes for a car that shakes hard, loses power or smells strongly of fuel.
Causes, ranked
| Cause | How you confirm it | Typical cost (US independent shop, 2026) |
|---|---|---|
| Worn spark plugs | Plugs past their interval; worn or eroded electrodes; misfire worse under load | $150–$350 a set (4-cyl), $250–$600 (V6/V8) |
| Vacuum leak making all cylinders lean | Lean codes like P0171; high fuel trims at idle; smoke test | $50–$400 |
| One or more failing ignition coils | Misfire counts follow a coil when it’s swapped to another cylinder | $120–$300 per coil |
| Fuel delivery: low pressure, dirty injectors, bad fuel | Fuel pressure test; lean on both banks; began after a fill-up | $150–$400 injector cleaning, $500–$1,200 fuel pump |
| Crank or cam sensor, timing problem | Sensor or timing codes like P0335; misfire counts that don’t match how the engine feels | $150–$400 sensor; timing work costs more |
| Low compression, coolant getting into cylinders | Compression or leak-down test; coolant level dropping; white exhaust smoke | $1,500–$4,500 |
V6 engines with rear plugs under the intake cost more for plugs and coils. The last row is the least common but the one to rule out if the misfire comes with coolant loss.
What to check first
- Read every stored code. Numbered misfire codes tell you which cylinders miss most; lean codes point to air or fuel; sensor codes point to timing.
- Check the plug service history. If the plugs are past their mileage, replace them first and look at the old ones for oil, coolant or cracks.
- Look for vacuum leaks by listening for hissing at idle, then with a smoke test.
- Swap coils between cylinders on coil-on-plug engines and see if the misfire follows.
- Test fuel pressure if the misfire is worse under load or on both banks.
- Clear it and drive only after a repair, never to get through an inspection.
Several makers have bulletins on this. GM has one covering cold-start misfire and rough idle on many models including the Blazer, Acadia, Regal and ATS, plus one replacing the charge air cooler on 2018–2021 Equinox models where moisture sets P0300. Ford has one for cold-start rough running on 2024 Mustangs with the 2.3L engine. Among owners, 448 complaints filed with NHTSA mention P0300, 35 for the Ford Escape, 17 of those for 2017 models. Those are owner reports, not confirmed causes.
What it costs
The cheap outcome is a vacuum hose or a set of plugs on a four-cylinder at $50–$350. The common outcome is plugs plus a coil or an injector cleaning, a few hundred dollars. The expensive outcome is a compression or coolant problem at $1,500–$4,500, or a $1,000–$2,500 converter if the misfire was ignored. Because P0300 doesn’t name a cylinder, diagnosis ($100–$180) matters more here than with any single-cylinder code.
Related codes
P0300 usually comes with numbered codes (P0303, P0304) that show where the misses concentrate, and a misfire left alone often leads to P0420. If the car shakes with the light on, see check engine light and car shaking.
What owners report to NHTSA
448 complaints filed with NHTSA mention P0300, 372 of them since 2015, across 151 different models. The component owners most often filed it under: engine.
Most-reported models
| Vehicle | Complaints | Model years reported |
|---|---|---|
| FORD ESCAPE | 35 | 2014, 2017, 2018, 2019, 2024 |
| FORD FUSION | 19 | 2015, 2016, 2017, 2018, 2019 |
| CHEVROLET SILVERADO 1500 | 18 | 2009, 2016, 2017, 2021, 2023 |
| HONDA ACCORD | 14 | 2011, 2014, 2016, 2018, 2019 |
| KIA SOUL | 13 | 2012, 2014, 2017, 2018, 2021 |
| HONDA CR-V | 11 | 2000, 2017, 2018, 2019 |
| GMC SIERRA 1500 | 11 | 2011, 2016, 2019, 2020, 2021 |
| FORD EDGE | 11 | 2016, 2017, 2018 |
| FORD F-150 | 10 | 2011, 2012, 2013, 2015, 2022 |
| CHEVROLET TAHOE | 10 | 2007, 2008, 2010, 2021, 2023 |
Manufacturer service bulletins that name P0300
1117 technical service bulletins and manufacturer communications filed with NHTSA mention P0300, from 40 makes. A bulletin means the manufacturer has documented a known cause or a fix procedure for that model. Examples:
- GENERAL MOTORS GENERAL MOTORS, bulletin 10172310: This Preliminary information communicates information that will need to be provided to TAC to aid in diagnosing if a vehicle comes in with misfire and DTC Codes P0300 - P0308 and/or P050D
- ACURA ACURA (2021, 2022, 2023, 2019), bulletin 10233209: Service Bulletin - Under certain circumstances, the vehicle may experience driveability concerns. This may result in the following DTCs to set: P0300 (Random Misfire Detected), P0301 (No. 1 Cylinder Misfire Detected), P0…
- BUICK REGAL (2018, 2019, 2009, 2010), bulletin 11006353: This service bulletin provides inspection/diagnosis/correction information on a cold start misfire and/or rough idle and DTC P0300 that may also be set.
- CADILLAC ATS (2013, 2014, 2015, 2016), bulletin 11006353: This service bulletin provides inspection/diagnosis/correction information on a cold start misfire and/or rough idle and DTC P0300 that may also be set.
- CHEVROLET BLAZER (2019, 2020, 2021, 2022), bulletin 11006353: This service bulletin provides inspection/diagnosis/correction information on a cold start misfire and/or rough idle and DTC P0300 that may also be set.
- GMC ACADIA (2007, 2008, 2009, 2010), bulletin 11006353: This service bulletin provides inspection/diagnosis/correction information on a cold start misfire and/or rough idle and DTC P0300 that may also be set.
Sources: NHTSA Office of Defects Investigation complaint database and manufacturer communications file, snapshots September 2026. A complaint or bulletin that mentions a code is a report about that vehicle, not a statement that the code has one cause.
Frequently asked questions
Can I drive with a P0300 code?
Only short, gentle trips, and only if the light is steady and the engine runs close to normal. Drive it to a shop or home, not on a road trip. If the check engine light is flashing or the car shakes hard, pull over and have it towed; a heavy misfire can overheat the catalytic converter within minutes.
What is the most common cause of P0300?
Worn spark plugs are the most common single answer on a car that's overdue for them, followed by vacuum leaks that make every cylinder run lean. Failing coils, low fuel pressure and dirty injectors come next. Internal engine problems like low compression are the least common and most expensive.
What is the difference between P0300 and P0301 to P0306?
The last digit tells you the cylinder. P0301 is cylinder 1, P0302 is cylinder 2, and so on; a single-cylinder code usually points to that cylinder's coil, plug or injector. P0300 means the misses are spread across cylinders or move around, which points to something they share.
Can bad gas cause P0300?
It can. Water in the fuel or a tank run nearly empty can make several cylinders miss at once. If the code appeared right after a fill-up and fades on the next tank of fuel from a busy station, that's the likely answer. If it keeps coming back, look at plugs, vacuum leaks and fuel pressure.
Will new spark plugs fix P0300?
If the plugs are worn or past their service interval, often yes, and it's the cheapest real fix. Look at the old plugs when they come out: oily, wet or cracked plugs point to another problem that new plugs won't cure. If the code returns within a few weeks, have the shop check for vacuum leaks and fuel pressure.
References
- NHTSA Office of Defects Investigation — vehicle owner complaint flat files
- NHTSA Office of Defects Investigation — manufacturer communications (service bulletin) flat files
- Cal. Code Regs. tit. 13, § 1968.2 — OBD II requirements, misfire monitoring and MIL blink rule (Cornell LII)
- 40 CFR § 86.1806-17 — Onboard diagnostics (Cornell LII)