P0300: Random/Multiple Cylinder Misfire Detected
244 vehicles · 35 makes · $20-$25,000 repair
Most Reported On
P0300 is an OBD-II diagnostic trouble code meaning “Random/Multiple Cylinder Misfire Detected.” The engine control module has detected misfires occurring randomly across multiple cylinders. This is the most common OBD-II code and can have many causes. A flashing check engine light with P0300 means active misfires that can damage the catalytic converter. This code is most commonly reported on 2004-2012 Mazda RX-8, 2011-2019 Hyundai Sonata (Base, GL, GLS, LX, Limited, SE, SEL, SEL Plus, Sport), and 2008-2021 Volkswagen Golf (GTI, GTI Autobahn, GTI S, GTI SE, Golf R, R, R32), plus 241 other vehicles, with repair costs ranging from $20 to $25,000.
Common Causes
Typical Repair Cost
Based on 311 documented vehicle-specific issues. Actual cost depends on root cause and vehicle.
Diagnostic Tools
To diagnose P0300, you'll need an OBD-II scanner. Here are our recommendations at every price point.
ANCEL AD310 Classic OBD-II Scanner
by ANCEL
A simple, affordable code reader that reads and clears check engine codes. Great for quick diagnostics on any OBD-II vehicle (1996+).
- Read & clear engine codes
- View freeze frame data
- I/M readiness status
- No batteries or app needed
BlueDriver Pro Bluetooth Scanner
by BlueDriver
Bluetooth OBD-II scanner with a free companion app. Provides enhanced diagnostics, smog readiness, and repair reports sourced from a database of verified fixes.
- Enhanced diagnostics (ABS, SRS, transmission)
- Repair Reports with verified fixes
- Smog check readiness
- Free app (iOS & Android)
LAUNCH CRP123X OBD-II Scanner
by LAUNCH
A professional-grade handheld scanner that reads all four major systems (engine, transmission, ABS, SRS) with live data streaming and graphing.
- Engine, transmission, ABS, SRS diagnostics
- Live data stream & graphing
- AutoVIN for vehicle identification
- Free lifetime updates via Wi-Fi
Autel MaxiCOM MK808S Diagnostic Tool
by Autel
Shop-level diagnostic tablet with bi-directional control, active tests, and full system coverage. Ideal for serious DIYers and small shops.
- All-system diagnostics (25+ modules)
- Bi-directional control & active tests
- Oil reset, EPB, BMS, TPMS, injector coding
- 7-inch touchscreen with Android OS
As an Amazon Associate, we earn from qualifying purchases. Prices are approximate and may vary.
Vehicles Affected (244)
Oil Consumption and Fouled Spark Plugs on 3.7L V6
Distributor internal shaft seal fails, oil leaks into cap and causes misfires + stalling
Distributor shaft seal leaks oil into cap, causes misfires (P0300-P0304) on 3.5L C35A
Intake Valve Carbon Buildup
Ignition Coil Failure
4.0T Direct Injection Carbon Buildup
4.0T Carbon Deposit Accumulation
3.0T Intake Valve Carbon Buildup
EA888 Carbon Buildup on Intake Valves
2.5T Five-Cylinder Carbon Buildup
Direct Injection Carbon Buildup
Severe Carbon Buildup on Intake Valves
Carbon Buildup on Intake Valves (4.2 V8 FSI and 5.2 V10 FSI)
Severe Carbon Buildup on Intake Valves (2.5T 5-Cylinder)
B6/B7 4.2L V8 Timing Chain Tensioner Failure
B5 S4 2.7T Timing Chain Guide Failure
Severe Carbon Buildup on Intake Valves (Direct Injection)
4.0T Carbon Buildup on Intake Valves
Carbon Buildup on Intake Valves (Direct Injection)
Carbon Buildup on Intake Valves (4.0T Twin-Turbo V8)
Intake Valve Carbon Buildup (Direct Injection)
Carbon Buildup on Intake Valves (2.0 TFSI Direct Injection)
Water Pump and Thermostat Housing Coolant Leaks
Coil Pack Failure and Ignition Misfires on 1.8T Engines
Severe Carbon Buildup on Intake Valves (Direct Injection Engines)
2.7T Ignition Coil Pack Failure Causing Misfires and Flashing Check Engine Light
Severe Carbon Buildup on Intake Valves (Direct Injection)
Direct Injection Carbon Buildup (Intake Valves)
4.2L V8 Carbon Buildup on Intake Valves
Carbon Buildup on Intake Valves (2.9T Twin-Turbo V6)
4.2L V8 Carbon Buildup and High-Rev Issues
Severe Carbon Buildup on Intake Valves (4.0T V8)
Turbo Wastegate Rattle and Carbon Buildup
Direct Injection Carbon Buildup on Intake Valves
Severe Carbon Buildup Causing Valve Damage (3.0T TFSI)
Water Pump Failure (60k Mile Lifespan)
Severe Carbon Buildup on Intake Valves (3.0T)
Carbon Buildup on Intake Valves (Pre-Dual Injection EA888 Gen 3)
Intake Valve Carbon Buildup
High-Pressure Fuel Injector Issues
Intake Valve Carbon Buildup
G80 S58 Engine Carbon Buildup on Intake Valves
S58 Intake Valve Carbon Buildup
S58 Intake Valve Carbon Buildup
N54 High-Pressure Fuel Pump (HPFP) Failure (135i / 1M)
S55 High-Pressure Fuel Injector Failure - F82/F83 M4
S63/S63TU Ignition Coil Premature Failure
N54 High Pressure Fuel Pump (HPFP) Failure - E89 Z4 sDrive35i/35is
N54 Spark Plug & Ignition Coil Failure (135i / 1M)
Carbon Buildup on Intake Valves (Direct Injection Engines)
Carbon Buildup on Intake Valves (Direct Injection Engines)
Ignition Coil Pack Failure Causing Misfires and Check Engine Light on M52TU/M54 Engines
S63/S63TU Valve Stem Seal Failure & Oil Consumption
Fuel Injector Failure - 428i/430i/435i/440i F32/F33/F36
CCV/Oil Separator Failure Causing Vacuum Leaks, Oil Consumption, and Cold-Weather Hydrolock Risk
Direct Fuel Injector Failure (S55)
Park Avenue 3800 V6 Lower Intake Manifold (LIM) Gasket Leak
Cascada 1.6L Turbo (Opel SIDI) Timing Chain & Carbon Buildup
Encore 1.4L Turbo (LUJ/LUV) Timing Chain Stretch
LaCrosse 3.6L LLT/LFX Timing Chain Stretch
LeSabre 3800 V6 Lower Intake Manifold (LIM) Gasket Leak
4.6L Northstar V8 Head Gasket Failure and Bolt Pull-Out
GM 6.2L V8 Engine Recall for Connecting Rod Bearing Failure
LT4 Supercharged V8 Premature Engine Failure
AFM/DOD Lifter Failure - V8 Cylinder Deactivation System
3.6L V6 Timing Chain Stretch and Premature Failure
Northstar 4.6L V8 Head Bolt/Head Gasket Failure
Northstar 4.6L V8 Head Bolt/Head Gasket Failure
Northstar 4.6L Head Bolt Thread Pull/Head Gasket Failure
Northstar 4.6L Head Gasket Failure
3.6L V6 Timing Chain Stretch - SRX
Northstar 4.6L V8 Head Bolt/Head Gasket Failure
3.6L V6 Timing Chain Stretch (ATS V6 models)
Excessive Oil Consumption - 6.2L EcoTec3 V8
6.2L L87 Connecting Rod/Bearing Failure Leading to Engine Seizure
LT1 5.7L Optispark Distributor Failure (1994-1996)
4.6L Northstar V8 Head Gasket Failure (1993)
Active Fuel Management Lifter Failure
5.3L Vortec AFM Active Fuel Management Oil Consumption and Lifter Failure
Duramax Diesel Injector Failure
Ignition Coil and Spark Plug Failure
Timing Chain Tensioner Failure
LT2 Engine Valve Lifter Tick and DFM Concerns
3.1L V6 Distributor Gear Wear Causing Timing Issues
AFM/DFM Lifter Failure (5.3L/6.2L V8)
5.7L Vortec Spider Injector Assembly Failure (CPI)
2.2L/2.4L Head Gasket Failure
2.2L OHV Head Gasket Failure
Ecotec 2.4L Timing Chain and Guide Failure
PCV Valve Cover Failure and Oil Leak (1.4T)
4.3L Vortec Central Sequential Fuel Injection (CSFI) Failure
Injector Wiring Harness Chafing (Duramax)
2.5L V6 Timing Chain Tensioner Failure
Head Gasket Coolant Leak and Overheating on 3.4L V6
Excessive Oil Consumption (2.5L Ecotec LCV/LKW)
AFM/DOD Lifter Failure - V8 Cylinder Deactivation
Cylinder Head Valve Seat Failure and Misfire on 3.5L/3.7L Inline-Five
L99 AFM Lifter Failure and Camshaft Damage on 6.2L Automatic Cars
HEMI 5.7L MDS Lifter and Camshaft Failure
Pentastar Cylinder Head Failure
2.7L V6 Engine Oil Sludge and Seizure
Chronic Overheating - Multiple Causes
Cooling System Failures (3.3L/3.8L V6)
Head Gasket Failure (Especially Turbo Models)
2.5L V6 Head Gasket Failure
Turbocharger Failure (GT/Turbo Models)
3.6L Pentastar Engine Stalling and Head Gasket Failure
3.5L V6 Head Gasket Failure and Overheating
5.7L HEMI MDS Lifter Tick and Camshaft Failure
Engine Oil Sludge Buildup (2.4L Non-Turbo)
HEMI MDS Lifter Tick
HEMI MDS Lifter Tick
Pentastar V6 Rocker Arm/Lifter Tick
HEMI Lifter/MDS Tick
2.7L V6 Engine Oil Sludge and Seizure
5.9L Magnum Plenum Gasket Failure
2.7L V6 Engine Oil Sludge Buildup and Failure
Pentastar V6 Rocker Arm/Lifter Tick
Cooling System Failures (3.3L/3.8L V6)
2.4L DOHC Head Gasket Failure
Engine Overheating - Thermostat Housing Debris
6G72 Timing Belt and Balancer Belt Failure
2.2L/2.5L Head Gasket Failure
2.4L Electronic Throttle Body Failure
Head Gasket Failure
2.2L/2.5L Head Gasket Failure
Gen 1 V10 Head Gasket Failure
Rod Bearing Failure from Oil Starvation (Track Use)
Engine Oil Sludge Buildup (3.6L Pentastar V6)
2.3L EcoBoost Head Gasket Failure and Coolant Intrusion
2.0L Direct Injection Carbon Buildup on Intake Valves
1.5L EcoBoost Coolant Intrusion into Cylinders - Engine Block Porosity
Fuel Injector Failure and Rough Running (EcoBlue Diesel)
2.0L EcoBoost Coolant Intrusion - Open-Deck Block Failure
1.6L EcoBoost Engine Overheating and Coolant Loss - Recall 14S11
1.5L EcoBoost 3-Cylinder Coolant Loss and Engine Failure
EcoBoost Coolant Intrusion into Cylinders
4.0L SOHC Timing Chain Cassette and Tensioner Failure
Ignition Coil Failure and Misfires (2.5L/1.6L)
Distributor Internal Coil and Sensor Failure
Head Gasket Failure and Coolant Leakage
2.3L HSC Head Gasket Failure
2.0L SPI Head Gasket Failure
3.8L V6 Head Gasket Failure
5.4L 2-Valve Spark Plug Blow-Out From Cylinder Head
6.0L Powerstroke Head Bolt Failure and Head Gasket Blowout
Ignition Coil Pack Failure
4.6L 2-Valve Spark Plug Ejection/Breakage
3.0L Vulcan V6 Head Gasket Failure
3.8L V6 Head Gasket Failure
2.3L EcoBoost Coolant Intrusion and Misfire from Cracked Cylinder Head/Head Gasket Area
Timing Chain Cassette and Guide Failure on 4.0L SOHC V6
AFM/DOD Lifter Collapse and Valvetrain Failure
AFM/DFM Lifter Collapse and Failure
LML Duramax EGR Cooler and EGR Valve Failure
6.0L V8 Excessive Oil Consumption and AFM Lifter Wear
AFM Lifter Failure on V8 Vortec/EcoTec3 Engines
Direct Injection Carbon Buildup on Intake Valves
4.3L Central Port Injection (CPI) Spider Injector Failure
Ecotec 2.4L Timing Chain and Tensioner Failure
5.7L Vortec Spider Injector Assembly Failure
Active Fuel Management (AFM) Lifter Failure (V6)
Active Fuel Management (AFM) Lifter Failure and Tick
5.7L Vortec Intake Manifold Gasket and CPI Issues
1.5T Earth Dreams Direct Injection Carbon Buildup on Intake Valves
Fuel Injector Debris Causing Misfires and Catalyst Codes
11th Gen 2.0T Direct Injection Carbon Buildup and Idle Vibration
Ignition Coil Failure
Idle and Stalling Problems
Spark Plugs Backing Out - Coil Pack Melting and Engine Damage
VCM System Oil Consumption and Engine Damage
EGR System Clogging (Lean Burn Engine)
Valve Cover Gasket and Spark Plug Tube Seal Oil Leaks Causing Misfires
Timing Belt and Water Pump Neglect Leading to 3.2L V6 Engine Damage
Distributor Internal Coil and Igniter Failure (4th Gen)
Theta II Engine Seizure/Failure
Theta II Engine Seizure Due to Connecting Rod Bearing Failure
Excessive Oil Consumption - 2.4L GDI Engine
Nu Engine Bearing Failure and Seizure
GDI Intake Valve Carbon Buildup
Head Gasket Failure (Mitsubishi G4DJ/G4EK)
Fuel Injector Failure Causing Misfire, Rough Running, and Check Engine Light
Valve Cover Gasket Oil Leaks Onto Spark Plug Wells and Exhaust Manifold
Theta II Engine Seizure / Recall
Knock Sensor / Engine Protection Logic Triggering Reduced Power and Check-Engine Light on 2.0L Models
Intake Manifold Gasket Leak
Head Gasket Failure (Shared Excel Platform)
HEMI Engine Tick/Lifter Noise
3.7L V6 Exhaust Manifold Crack / Valve Cover Oil Leaks
Fuel Injector Leak / Fuel Smell in Engine Bay (3.0L Hurricane)
Ignition Coil Rail Failure Causing Misfire on 4.0L
Intake Valve Carbon Buildup (GDI Engines)
Fuel Injector Failure and Engine Stalling
3.8L Lambda V6 Timing Chain Stretch and Rattle
3.3L Lambda II GDI V6 Connecting Rod Bearing Failure
5.0L Tau V8 Timing Chain and GDI Injector Issues
Timing Belt Neglect Leading to Bent Valves and Sudden No-Start on 1.6L Engines
Ignition Coil and Plug Wire Failure Causing Misfire, Hesitation, and Check Engine Light
Ignition Coil Pack Failure Causing Misfire
Carbon Buildup on Intake Valves (2.0T)
Carbon Buildup on Intake Valves (2.0T)
Valve Cover Gasket Leaks Causing Oil Smell and Misfire Risk
V35A-FTS 3.4L Twin-Turbo V6 Main Bearing / Engine Failure Risk Covered by Toyota-Lexus Recall
Apex Seal Failure / Compression Loss
Crankshaft Position Sensor Failure (NB)
Carbon Buildup on Direct Injection Intake Valves
Carbon Buildup on Intake Valves (Skyactiv)
Timing Chain Guide and Tensioner Failure
Ignition Coil Failure and Misfires
Distributor Internal Coil and Hall Effect Sensor Failure
Skyactiv 2.0L Intake Valve Carbon Buildup
Distributor Failure on V6 Models
N14/N18 Turbo Engine Timing Chain Catastrophic Failure
Direct Injection Carbon Buildup on Intake Valves
N12/N16 Timing Chain Tensioner Failure
Intake Valve Carbon Buildup from Direct Injection
Carbon Buildup on Intake Valves (Direct Injection) Causing Misfires/Power Loss
Oil Separator / Crankcase Ventilation Valve Failure Causing Oil Consumption (N14/N18)
Turbocharger Oil Feed Line Leak and Carbon Buildup
B38/B48 Engine Timing Chain Stretch and Rattle
N14/N18 Timing Chain Tensioner Failure and Chain Stretch
VVEL Solenoid Failure (VK56VD Engine)
Timing Chain Rattle and Failure (QR25DE 4-Cylinder)
Ignition Coil Failure (VQ35DE)
Excessive Oil Consumption (QR25DE)
Ignition Coil Failure
VQ35DE Timing Chain Stretch and Guide Wear
Distributor / Ignition System Failure Causing Sudden Stall or No-Start
2.5L Pre-Catalyst Breakdown Causing Excessive Oil Consumption and Engine Damage
Bonneville 3800 V6 Lower Intake Manifold (LIM) Gasket Failure
Grand Prix 3800 V6 Lower Intake Manifold (LIM) Gasket Failure
Grand Am 3.4L V6 Upper/Lower Intake Gasket Failure
Firebird LT1 Optispark Distributor Failure
G6 2.4L Ecotec (LE5/LAT) Timing Chain Stretch
Montana 3.4L V6 Intake Gasket — Same as Grand Am
Vibe 1.8L (1ZZ-FE) Oil Consumption — Coked Piston Rings
Cylinder Bore Scoring (Nikasil Wear)
Cylinder Bore Scoring
Cylinder Bore Scoring
Direct Injection Intake Valve Carbon Buildup
Timing Chain Tensioner and Guide Failure
Direct Injection Intake Valve Carbon Buildup
6.7L Cummins Exhaust Brake Actuator and VGT Turbo Issues
HEMI Lifter/Camshaft Failure
5.7L HEMI MDS Lifter Failure
MDS Lifter Failure and Hemi Tick (5.7L)
Head Gasket Failure
EJ253 Head Gasket Failure (External Leak)
EJ25 Head Gasket Failure
EJ25 Head Gasket Failure
Spun Rod Bearing Failure (EJ257)
Head Gasket Issues
FA20 Valve Spring Recall - Engine Stalling Risk
EZ36 Timing Chain Stretch and Guide Wear
EJ257 Piston Ringland Failure
EZ30 3.0L H6 Head Gasket Leak
Valve Spring Recall - Engine Stall Risk
EGR Valve and Intake Manifold Carbon Buildup
Water Pump Leak and Failure (2GR-FE)
1NZ-FXE Head Gasket Failure and EGR Cooler Issues
2.4L 2AZ-FE Excessive Oil Consumption
G16E-GTS Head Gasket Seepage Under Hard Use
Head Gasket Failure
Head Gasket Failure (5E-FE)
2.4L 2AZ-FE Head Gasket and Head Bolt Thread Failure
2AZ-FE Excessive Oil Consumption From Piston/Ring Wear
Head Gasket Failure (Supercharged Models)
Intake Manifold Gasket Vacuum Leak Causing Cold-Start Rough Idle and Lean Codes
1GR-FE V6 Head Gasket Failure with External Coolant Leak at Rear of Cylinder Head
3.4L 5VZ-FE Head Gasket Failure
22R-E Head Gasket Failure
2AZ-FE Excessive Oil Consumption from Piston/Ring Wear
Excessive Oil Consumption from 1ZZ-FE Piston Ring Wear
FA20 Valve Spring Recall (Campaign E0G/17V-587)
Direct Injection Carbon Buildup on Intake Valves
Ignition Coil Pack Failure (All Engines)
Intake Valve Carbon Buildup
2.5L 5-Cylinder Ignition Coil Pack Failure
Ignition Coil Failure
2.0 TSI Timing Chain Tensioner Failure (CCTA/CBFA)
EA211 1.5T Engine Ticking and Fuel Injector Noise
EA888 Gen 3 Intake Valve Carbon Buildup (GDI)
Ignition System and Distributor Failure
Ignition Coil Pack Cracking and Misfires
Direct Injection Carbon Buildup on Intake Valves
PCV Valve/Diaphragm Failure
VR6 Timing Chain Tensioner Failure
2.0L Ignition Coil Pack Failure
VR6 Cylinder Head Cracking
PCV Valve Diaphragm Failure
Ignition Coil Pack Failure (1.8T/2.0)
2.5L I5 Timing Chain Tensioner Failure
Timing Belt and Water Pump Failure
FAQ
What does P0300 mean?
P0300 stands for "Random/Multiple Cylinder Misfire Detected." The engine control module has detected misfires occurring randomly across multiple cylinders. This is the most common OBD-II code and can have many causes. A flashing check engine light with P0300 means active misfires that can damage the catalytic converter.
What are the most common causes of P0300?
The most common causes of P0300 are: Worn spark plugs or ignition coils, Vacuum leak, Low fuel pressure, Clogged fuel injectors, EGR valve malfunction, Low compression, Timing chain stretch. The specific cause varies by vehicle.
How much does it cost to fix P0300?
Repair costs for P0300 range from $20 to $25,000, depending on the vehicle and root cause.
Which vehicles are affected by P0300?
Au7o has documented P0300 across 244 vehicle models from 35 manufacturers: Acura, Audi, BMW, Buick, Cadillac, Chevrolet, Chrysler, Citroën, Dodge, Ford, GMC, Honda, Hyundai, Infiniti, Jeep, Kia, Land Rover, Lexus, Lincoln, MINI, Mazda, Nissan, Opel, Pontiac, Porsche, RAM, Renault, SEAT, Saab, Skoda, Subaru, Suzuki, Toyota, Volkswagen, Volvo.
Sources (12)
- RecallNHTSA Recall 17V-224
- manufacturerFreelander Specialist: Freelander 1.8 K Series Head Gasket Replacement
- manufacturerFreelander Specialist: Land Rover Freelander Head Gasket Blown What Causes it?
- ForumLand Rovers Only: K Series head gasket problem
- ForumPistonHeads: Freelander Head Gasket issues?
- ForumLandyZone: Head Gasket Failure
- ForumMG-Rover: Land Rover Freelander V6 head gasket failure
- manufacturerFreelander Specialist: Freelander 2.5 Petrol K V6 Head Gasket Replacement
- ForumLandyZone: KV6 engine reliability after re-design
- ForumLandyZone: Freelander 1 KV6 Head Gasket failure
- ForumLand Rovers Only: 2003 Freelander KV6 2.5 blown head gasket repair
Content compiled with AI assistance using NHTSA complaints, TSBs, and owner reports. May contain errors. Always verify with your vehicle's service manual.