P0300: Random/Multiple Cylinder Misfire Detected
What Does P0300 Mean?
P0300 is a diagnostic trouble code indicating: Random/Multiple Cylinder Misfire Detected. This code relates to the ignition system system. It has been reported in NHTSA complaints across 60 different vehicle models.
The P0300 code is set when the Engine Control Module (ECM) detects misfires occurring across multiple cylinders rather than being isolated to a single cylinder. The ECM monitors crankshaft speed variations — each time a cylinder fires, the crankshaft accelerates slightly. When a cylinder misfires, that acceleration is missing, and the ECM detects the drop. A random misfire means the problem jumps between cylinders rather than staying on one, which typically points to a system-wide issue rather than a component failure in a single cylinder. This is important because random misfires that jump around (setting both P0300 and individual cylinder codes like P0301-P0306) often indicate a lean fuel condition caused by a vacuum leak, unmetered air getting past the MAF sensor, or an EGR valve stuck open. If the check engine light is flashing while the engine is running, this indicates active misfires that can overheat and destroy the catalytic converter — in that case, reduce speed immediately and get the vehicle to a mechanic as soon as possible.
Symptoms of P0300
- ⚠️ check engine light (often flashing)
- ⚠️ rough idle
- ⚠️ loss of power
- ⚠️ engine vibration
- ⚠️ increased emissions
- ⚠️ poor fuel economy
Common Causes
- 🔍 Worn or fouled spark plugs
- 🔍 Faulty ignition coils or spark plug wires
- 🔍 Vacuum leak
- 🔍 Low fuel pressure (weak pump or clogged filter)
- 🔍 Clogged or dirty fuel injectors
- 🔍 EGR valve stuck open
P0300 Reports by Year
Real Owner Reports
From NHTSA complaint database — actual owner descriptions.
"1. The 3.5L V6 Engine (2GR-FE) failed due to the subsequent loss of lubrication caused by the rupture of the Oil Cooler Pipe (Rubber component), a manufacturing defect known under TSB T-SB-0201-11 (ZE2 Program). The failed engine is currently available for inspection by request at the independent se"
— Toyota Highlander owner, 10/08/2025
"I experienced a sudden engine failure while driving my 2015 Toyota Highlander on Interstate 294 outside Chicago. I was driving about 75 mph in the far left lane. A warning message "Check AWD" came on the screen, followed by the Engine icon lighting up, then a "TRAC off" message appeared on the scree"
— Toyota Highlander owner, 07/22/2023
"ON JUNE 7, 2019, I WAS DRIVING THE AVALON, THE ENGINE SUDDENLY STOPPED WHILE I WAS DRIVING THE VEHICLE ON CITY STREET. WITH THE LOSS OF POWER STEERING AND BRAKES, I WAS TRAUMATIZED AND DID MY BEST TO GUIDE THE VEHICLE TO SIDE OF THE ROAD. I HAD THE VEHICLE TOWED HOME AND HOOKED UP TO A CODE READE"
— Toyota Avalon owner, 06/07/2019
Source: NHTSA Complaints Database
Most Reported Vehicles for P0300
Based on NHTSA owner complaint data.
| # | Vehicle | Reports |
|---|---|---|
| 1 | FORD ESCAPE | |
| 2 | FORD FUSION | |
| 3 | HONDA ACCORD | |
| 4 | KIA SOUL | |
| 5 | CHEVROLET TRAVERSE | |
| 6 | CHEVROLET TAHOE | |
| 7 | FORD EDGE | |
| 8 | HONDA CR-V | |
| 9 | CHEVROLET MALIBU | |
| 10 | HYUNDAI TUCSON | |
| 11 | JEEP GLADIATOR | |
| 12 | HONDA FIT | |
| 13 | HONDA PILOT | |
| 14 | FORD MUSTANG | |
| 15 | CHEVROLET EQUINOX |
P0300 Reports by Vehicle
Detailed NHTSA complaint analysis for each vehicle model.
Diagnostic Tips
- Scan all modules, save freeze-frame data, and clear unrelated history codes before focusing on P0300.
- Confirm whether companion codes are present first; they often identify the root cause sooner than the headline DTC.
- Prioritize inspection around engine and the most common failure path for this code family.
- Review Mode $06 misfire counters and swap coils/plugs between cylinders to see if the fault follows the component.
- After each repair step, complete one drive cycle and verify readiness monitors instead of judging success after a quick idle test.
- If the code keeps returning on high-incidence platforms (for example FORD ESCAPE), check TSB patterns and wiring/connector fitment before major part replacement.
Common Mistakes to Avoid
- ❌ Skipping freeze-frame review and losing the exact RPM/load conditions when the fault set.
- ❌ Replacing injectors or converters before confirming spark quality and mechanical compression across cylinders.
- ❌ Clearing P0300 and returning the car before monitors complete — this often creates repeat visits.
- ❌ Treating intermittent wiring or connector faults as permanent component failure without wiggle testing.
Frequently Asked Questions
Can I drive with a P0300 code?
What is the most common fix for P0300?
Why does P0300 appear with other misfire codes?
How much does it cost to fix a P0300 code?
Reported Repair Costs for P0300
Based on 22 owner-reported repair costs from NHTSA complaints.
⚠️ These are owner-reported costs, not estimates. Actual costs vary by location, labor rates, and root cause. Source: NHTSA complaints database.
What To Do Next
Possible Fixes
- 🔧 Replace spark plugs
- 🔧 Replace ignition coils
- 🔧 Repair vacuum leaks
- 🔧 Replace fuel pump or filter
- 🔧 Professional fuel injector cleaning
-
1
Find your vehicle above
Click your make and model for real owner reports and common causes specific to your vehicle.
-
2
Check for recalls
Go to nhtsa.gov/recalls and enter your VIN. Free repairs if covered.
-
3
Get a professional diagnosis
A code alone doesn't identify the exact failed part. A diagnostic ($50–$150) pinpoints the root cause.