P0300: Random/Multiple Cylinder Misfire Detected
254 vehicles · 42 makes · $20-$25,000 repair
Most Reported On
P0300 is an OBD-II diagnostic trouble code meaning “Random/Multiple Cylinder Misfire Detected.” P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously. 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 251 other vehicles, with repair costs ranging from $20 to $25,000.
Common Causes
Typical Repair Cost
Based on 396 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 (254)
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
Oil Consumption and Fouled Spark Plugs on 3.7L V6
Cylinder Misfire Diagnosis and Ignition-Coil Failure — 2.7T APB/BEL
Fuel-Quality or Deposit-Related Rough Running and Misfire Diagnosis
2009-2025 Q5 Gasoline-Quality Deposit Diagnosis - TSB 2014753/13
2009-2021 A4 2.0T Gasoline-Quality Deposit Diagnosis - TSB 2014753/13
2010-2011 A4/A4 Avant CAEB Bosch Ignition-Coil Diagnosis - TSB 2033561/2
2019-2021 A6 3.0L Misfire Codes - Check ECM Software Before Mechanical Cleaning
2007-2008 RS4 Deposit-Related Cold-Start Misfire - Diagnose Before Cleaning
Intake Valve Carbon Buildup
G80 S58 Engine Carbon Buildup on Intake Valves
S58 Intake Valve Carbon Buildup
S58 Intake Valve Carbon Buildup
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
Direct Fuel Injector Failure (S55)
S63 Carbon Buildup on Intake Valves (Direct Injection)
S63/S63TU Valve Stem Seal Failure & Oil Consumption
S63 High-Pressure Fuel Pump / Fuel Injector Cold-Start Misfire
Valve Cover Gasket Oil Leak (M52/M54 6-Cylinder)
Engine Stalling and Sudden Power Loss While Driving (Early Models)
Optispark (Opti-Spark) distributor failure on the LT1
Cascada 1.6L Turbo (Opel SIDI) Timing Chain & Carbon Buildup
Encore 1.4L Turbo (LUJ/LUV) Timing Chain Stretch
Park Avenue 3800 V6 Lower Intake Manifold (LIM) Gasket Leak
Stretched/Worn Timing Chain on 3.6L V6
Carbon Buildup on Intake Valves (Direct Injection)
LaCrosse 3.6L LLT/LFX Timing Chain Stretch
LeSabre 3800 V6 Lower Intake Manifold (LIM) Gasket Leak
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
Excessive Oil Consumption & AFM Lifter Failure (5.3L V8)
LT2 Engine Valve Lifter Tick and DFM Concerns
4.3L V6 CPI/CSFI "Spider" Fuel Injector Leaks and Poppet Valve Failure
5.3L Vortec 5300 (Gen IV LC9/LMG) Excessive Oil Consumption from Piston Rings/AFM
Excessive Oil Consumption on 3.6L LFY (Worn Rings / PCV)
Broken Exhaust Manifold Bolts (Startup Ticking)
3.1L V6 Distributor Gear Wear Causing Timing Issues
2.2L/2.4L Head Gasket Failure
PCV Valve Cover Failure and Oil Leak (1.4T)
2.5L V6 Timing Chain Tensioner Failure
Head Gasket Coolant Leak and Overheating on 3.4L V6
5.3L AFM Excessive Oil Consumption (Low-Tension Piston Rings / Oil Spray)
CSFI 'Spider' Central Port Injector / Poppet Valve Failure (5.7L Vortec)
5.7L Vortec CSFI 'Spider' Poppet Injector Failure
Intake Manifold Gasket Vacuum Leak (Rough Idle, Cold-Start Misfire, Lean Codes)
Ignition Coil and Spark Plug Misfire from Valve Cover Gasket Oil Leak (1.8L)
Distributor cap and rotor moisture corrosion (frequent replacement)
LT1 Optispark distributor failure (moisture/oil/coolant intrusion)
3.4L V6 (L32) intake and head gasket failure
CSFI "spider" poppet fuel injector failure (special coverage 99066F)
4.3L Vortec CSFI "Spider" Injector Poppet Valve Leaking/Clogging
CSFI/CPI "Spider" Fuel Injector Assembly Failure (Poppet Valve Leaks)
1.5L Turbo Intake Valve Carbon Buildup Causing Misfires and Rough Cold Start (GDI)
1.5L Turbo Fuel Injector Leak Causing Misfire, Fuel Odor and Rough Running
2.4L Exhaust Manifold Cracking Causing Exhaust Leak and Cabin Fumes
CSFI/CPI 'Spider' Fuel Injector Assembly Failure (Misfire, Rough Idle, Poor Fuel Economy)
6.2L L87 Rod-Bearing Engine Failure (Recall 25V-274)
5.3L Vortec Excessive Oil Consumption (Low-Tension Rings / PCV)
5.3L V8 Active Fuel Management (AFM) Lifter Collapse and Camshaft Damage
AFM/DFM Lifter Failure (5.3L/6.2L V8)
5.7L Vortec Spider Injector Assembly Failure (CPI)
2.2L OHV Head Gasket Failure
Ecotec 2.4L Timing Chain and Guide Failure
4.3L Vortec Central Sequential Fuel Injection (CSFI) Failure
Injector Wiring Harness Chafing (Duramax)
5.3L V8 (AFM) excessive oil consumption fouling spark plugs
AFM/DOD Lifter Failure - V8 Cylinder Deactivation
5.3L V8 (AFM/DFM) collapsed/failed lifter causing ticking and cylinder misfire
2.7L TurboMax (L3B) lifter failure, intake-valve carbon buildup, and high oil consumption
Excessive Oil Consumption (2.5L Ecotec LCV/LKW)
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
3.6L V6 Direct-Injection Intake Valve Carbon Buildup
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
3.6L Pentastar Valvetrain Failure (Rocker Arm / Lifter Ticking, Misfire, Engine Damage)
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
Head Gasket Failure
2.4L Electronic Throttle Body 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)
Valve Spring Failure on 6.4L 392 HEMI (High-RPM and Modified/Boosted Cars)
Random Misfire / Rough Idle (P0300) From Worn Spark Plugs & Failing Ignition Coils
Intake Plenum Pan Gasket Failure (Magnum V6/V8) Causing Oil Consumption and Misfire
Interference-engine timing belt / hydraulic tensioner failure
2.0L head gasket failure (original composite gasket) — SOHC and DOHC
3.6L Pentastar V6 Left Cylinder Head Failure (Misfire on Cylinders 2/4/6)
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
3.5L EcoBoost Intercooler Condensation Causing Shudder and Limp Mode
5.4L 3-Valve Triton Two-Piece Spark Plug Snaps Off Inside the Cylinder Head During Removal
3.5L EcoBoost (Gen 1) Intake Valve Carbon Buildup — Misfire, Rough Idle, Power Loss
4.6L 2-Valve Triton V8 Spark Plug Ejection / Stripped Head Threads (TSB 07-21-2)
3.8L Essex V6 Head Gasket Failure
5.0 Spark Plug Wire Melt-Through on Exhaust Manifolds (Misfire)
4.6L SOHC Composite Intake Manifold Coolant Crossover Cracking
Dropped intake valve seat on the 1.9L CVH (cylinder #4)
Distributor internal oil seal failure contaminates crank/cam sensor, causing stalling and no-start
4.0L OHV cracked cylinder heads and blown head gaskets from overheating
4.0L SOHC timing chain cassette, guide, and tensioner failure
1.6L EcoBoost Intake-Valve Carbon Buildup (Direct Injection)
4.0L SOHC / OHV Waste-Spark Coil Pack Misfire (P0300 Series)
Intake-Valve Carbon Buildup on Direct-Injected EcoBoost Engines Causing Rough Idle and Misfire
2.3L EcoBoost Coolant Intrusion and Misfire from Cracked Cylinder Head/Head Gasket Area
Ignition Coil Pack Failure
3.5L EcoBoost Fuel Injector Failure — Startup Misfire, Rough Idle, and Fuel-Injector DTCs
Coil-On-Plug (COP) Ignition Coil Failure — Misfire and Rough Idle (Triton V8)
3.8L V6 Head Gasket Failure
2.0L SPI Head Gasket Failure
3.5L EcoBoost Ignition Coil and Spark Plug Misfire (Often Caused by Broken Exhaust Manifold Studs)
Timing Chain Cassette and Guide Failure on 4.0L SOHC V6
5.4L 2-Valve Spark Plug Blow-Out From Cylinder Head
6.0L Powerstroke Head Bolt Failure and Head Gasket Blowout
Ignition Coil / Spark Plug Misfire — Oil-Fouled Coils & Water Ingress in Plug Wells
4.6L 2-Valve Spark Plug Ejection/Breakage
3.0L Vulcan V6 Head Gasket Failure
3.8L V6 Head Gasket Failure
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
5.3L V8 Excessive Oil Consumption (AFM Oil Spray / Piston Rings)
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
Valve Cover Gasket and Spark Plug Tube Seal Oil Leak Causing Misfires
K24Z Sticking Piston Rings — Excessive Oil Consumption (3rd Gen)
1.5T Turbo Engine Coolant Intrusion Into Cylinders / Head Gasket Degradation (Class Action)
1.5L Turbo Coolant Intrusion into Cylinders / Head Gasket Coolant-Slot Defect
8th-Gen 1.8L Cracked Engine Block — Coolant Leak and Overheating (R18 Casting Defect)
Valve Cover Gasket Oil Leak — Burning Smell and Oil in Spark-Plug Wells
1.5T Cold-Weather Misfire from Fuel Injector Leakage — PGM-FI Software (TSB A19-033)
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)
1.5L Turbo (L15BE) Engine Oil Dilution — Fuel in Oil, Overfilled Dipstick, Gas Smell in Cabin
Cold-Start Rough Idle / Vibration on 1.5L Turbo (Linked to Oil Dilution & Misfire)
VCM System Oil Consumption and Engine Damage
EGR System Clogging (Lean Burn Engine)
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 (Shared Excel Platform)
Head Gasket Failure (Mitsubishi G4DJ/G4EK)
Theta II Engine Seizure / Recall
Intake Manifold Gasket Leak
Fuel Injector Failure Causing Misfire, Rough Running, and Check Engine Light
Valve Cover Gasket Oil Leaks Onto Spark Plug Wells and Exhaust Manifold
Knock Sensor / Engine Protection Logic Triggering Reduced Power and Check-Engine Light on 2.0L Models
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)
2011-2013 3.6L Left-Head Misfire - Follow the X56 Leak-Down Test
4.0L 0331 Cylinder Head Casting Cracking Between #3 and #4 Cylinders
3.6L Pentastar Rocker Arm / Lifter Needle-Bearing Failure — Valvetrain Tick, Misfire & Cam Damage
3.6L Pentastar V6 left cylinder head failure / engine tick (early build)
Early 3.6L Pentastar Left Cylinder Head Valve Seat/Guide Wear Causing Misfires (Warranty Extension X56 / TSB 09-002-14)
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
Ignition Coil Pack Failure Causing Misfire
Engine Valve Spring Fracture / Loss of Motive Power (3.8L V6, Recall SC296)
Stalling and Fire Hazard on Unrepaired / Still-Symptomatic 2021-2023 2.0L Vehicles
P0300 — Random/Multiple Misfire from Theta II GDI Ignition Coils, Carbon Buildup, or Low Oil / CVVT Starvation
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
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
Distributor Cap & Rotor Cracking / Ignition Misfire (Non-VVT-i 1992-1997)
5.4L 3-Valve Triton Spark Plugs Seize and Break in Cylinder Head
2.0L EcoBoost Internal Coolant Leak / Coolant Intrusion into Cylinders
Navigator 5.4L 3V Triton Spark Plug Breakage on Removal
Navigator 3.5L EcoBoost Timing Chain Stretch
Coil-on-Plug Ignition Coil Failure and Misfires (4.6L V8)
Apex Seal Failure / Compression Loss
Crankshaft Position Sensor Failure (NB)
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
Cylinder Deactivation Rocker Arm Dislodgement / Engine Stall (Recall 19V-497)
2012-2013 Mazda3 SKYACTIV Cold-Start Misfire from Intake-Valve Deposits
Ignition Coil and Spark Plug Rapid Wear Causing Misfires
KL V6 distributor internal oil seal leak / cap-and-rotor fouling
Head gasket failure / chronic overheating (age and cooling neglect)
Distributor Failure on V6 Models
Skyactiv 2.0L Intake Valve Carbon Buildup
SkyActiv-G Intake Valve Carbon Buildup (Direct Injection)
M282 1.3L Intake Valve Carbon Buildup
Carbon Buildup on Intake Valves (Direct-Injection M260) Causing Rough Idle and Power Loss
M260 Cylinder Head Exhaust Valve Seat/Guide Wear (Misfires, Compression Loss)
M177 4.0L Twin-Turbo V8 Excessive Oil Consumption and Cylinder Scoring
M157 5.5L Biturbo V8 Cylinder Scoring and Camshaft Adjuster Wear (Pre-Facelift G 63)
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)
Distributor / Ignition System Failure Causing Sudden Stall or No-Start
Ignition Coil Failure (VQ35DE)
QR25DE Ignition Coil Failures Causing Misfires (Cylinders 1 and 4)
2.5L QR25DE Head Gasket Failure Causing Coolant Loss and Overheating
Optical distributor failure (VG30E/VG33E) causing misfire, rough idle, stalling and no-start
GA16DE valve cover gasket and spark-plug-tube seal oil leak (oil in the plug wells)
1.5L VC-Turbo Main/Link Bearing Seizure Causing Engine Knock, Stall, and Total Engine Failure (Recall)
Timing Chain Rattle and Failure (QR25DE 4-Cylinder)
Excessive Oil Consumption (QR25DE)
Ignition Coil Failure
VQ35DE Timing Chain Stretch and Guide Wear
2.5L Pre-Catalyst Breakdown Causing Excessive Oil Consumption and Engine Damage
Plastic Upper Intake Manifold (Plenum) Degradation and Coolant Ingestion (3800 Series II)
Bonneville 3800 V6 Lower Intake Manifold (LIM) Gasket Failure
Grand Am 3.4L V6 Upper/Lower Intake Gasket Failure
Firebird LT1 Optispark Distributor Failure
Montana 3.4L V6 Intake Gasket — Same as Grand Am
Vibe 1.8L (1ZZ-FE) Oil Consumption — Coked Piston Rings
Grand Prix 3800 V6 Lower Intake Manifold (LIM) Gasket Failure
G6 2.4L Ecotec (LE5/LAT) Timing Chain Stretch
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
4.7L PowerTech V8 Head Gasket Failure / Coolant Intrusion and Valve-Seat Drop After Overheat
5.2L/5.9L Magnum Intake Manifold Plenum Pan Gasket Failure (Oil Burning, Misfire, Cat Damage)
5.7L HEMI Dropped Valve Seat (Pre-2009 Engines) Causing Misfire and Catastrophic Engine Damage
3.6L Pentastar Rocker Arm Roller Bearing Failure Wiping Camshaft ('Pentastar Tick', Misfire)
6.7L Cummins Exhaust Brake Actuator and VGT Turbo Issues
HEMI Lifter/Camshaft Failure
5.7L HEMI MDS lifter collapse and camshaft lobe wear ("HEMI tick" leading to engine damage)
MDS Lifter Failure and Hemi Tick (5.7L)
6.4L HEMI Valvetrain Failure (Roller Lifter/Camshaft Wear, "HEMI Tick")
5.7L HEMI MDS Lifter Failure
3.0L Hurricane Twin-Turbo I6 Random Misfire (P0300) on Early-Build Trucks Needing ECU/Ignition Reflash
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
Phase I EJ25D DOHC 2.5L Internal Head Gasket Failure
Distributor Cap, Rotor, and Ignition Moisture Misfire (SOHC EJ18/EJ22)
EZ30 3.0L H6 Head Gasket Leak
Valve Cover Gasket and Spark Plug Tube Seal Oil Leak Causing Misfires (FB25)
FA24 2.4L Turbo Direct-Injection Intake-Valve Carbon Buildup (XT / Wilderness / Onyx Turbo Models)
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)
2GR-FE Valve Cover Gasket & Spark-Plug Tube Seal Oil Leak (Oil-Fouled Coils / Misfire)
1GR-FE 4.0L V6 Head Gasket Failure on Early 2005-2006 Models (Coolant Loss and Cold-Start Misfire)
Ignition Misfires: Distributor Cap/Rotor, Plug Wires and Distributor Oil-Seal Contamination
Head Gasket Failure on the 2TZ Mid-Engine (Overheating-Induced)
Intake Manifold Gasket Vacuum Leak Causing Cold-Start Rough Idle and Lean Codes
Ignition Coil and Intake/PCV Failure Causing Random Misfire (2.7L 1AR-FE / 2GR V6) — P0300
2.4L 2AZ-FE Head Gasket and Head Bolt Thread Failure
Head Gasket Failure (Supercharged Models)
Excessive Oil Consumption from 1ZZ-FE Piston Ring Wear
Ignition Coil-On-Plug Failure Causing Misfire and P0351/P030x 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
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
Ignition Coil Failure
2.5L 5-Cylinder Ignition Coil Pack 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)
W12 Ignition Coil Failure Causing Misfires and Rough Running
Ignition System and Distributor Failure
2.0 TSI direct-injection carbon build-up on intake valves
EA888 Direct-Injection Carbon Buildup on Intake Valves
EA888 Excessive Oil Consumption (Piston Ring Defect)
2.0T EA888 Intake Valve Carbon Buildup Causing Cold-Start Misfires
Ignition Coil Pack Cracking and Misfires
Ignition Coil Pack Failure Causing Misfires (2.0 ABA and VR6)
VR6 coil pack casing cracking causing misfires (worse in wet weather)
2.5L I5 Timing Chain Tensioner Failure
Direct Injection Carbon Buildup on Intake Valves
PCV Valve/Diaphragm Failure
VR6 Timing Chain Tensioner Failure
Timing Belt and Water Pump Failure
2.0L Ignition Coil Pack Failure
VR6 Cylinder Head Cracking
PCV Valve Diaphragm Failure
Ignition Coil Pack Failure (1.8T/2.0)
Carbon Buildup on Intake Valves (Direct Injection)
Ignition Coil Pack Failure Causing Misfires and Power Loss
Intake Valve Carbon Buildup on the GDI 1.5 TSI
2.0 TSI/FSI Carbon Buildup on Intake Valves (Direct Injection)
FAQ
What does P0300 mean?
P0300 stands for "Random/Multiple Cylinder Misfire Detected." P0300 means the engine computer detected misfires occurring randomly or across multiple cylinders rather than in one specific cylinder. A misfire is when a cylinder fails to ignite its fuel-air mixture properly, which the computer senses through small fluctuations in crankshaft speed. Because it's not isolated to one cylinder, the cause is usually something that affects the whole engine — like fuel, air, or ignition system problems — rather than a single coil or plug. Persistent or heavy misfiring wastes fuel, runs rough, and can damage the catalytic converter, which is why a flashing check engine light should be taken seriously.
What are the most common causes of P0300?
The most common causes of P0300 are: Worn or fouled spark plugs (across cylinders), Vacuum or intake air leak, Weak fuel pump, clogged fuel filter, or low fuel pressure, Failing ignition coils or worn spark plug wires, Dirty or faulty mass airflow (MAF) sensor, Clogged or dirty fuel injectors, Faulty crankshaft/camshaft position sensor, Low compression or EGR/PCV system faults. 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 254 vehicle models from 42 manufacturers: Acura, Audi, BMW, Buick, Cadillac, Chevrolet, Chrysler, Citroen, Dodge, Ford, GMC, Genesis, Honda, Hyundai, Infiniti, Jaguar, Jeep, Kia, Land Rover, Lexus, Lincoln, MINI, Mazda, Mercedes-Benz, Mitsubishi, Nissan, Opel, Peugeot, Pontiac, Porsche, RAM, Ram, Renault, SEAT, Saab, Saturn, 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.