Car Repair Questions Diagrams Auto Manuals Auto Repair Estimates Auto Repair

P0300 - Cylinder Misfire Detected Random Cylinders.

When your engine starts running rough and the check engine light comes on, you can almost bet that you are going to see an Engine Misfire Code.

engine misfire

P0300 Description

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring.

Engine Misfire Symptoms

  • Engine Light ON (or Service Engine Soon Warning Light)
  • Lack/loss of power
  • Hard start
  • Engine hesitation

Engine Misfire Causes

  • Faulty spark plug (s)
  • Faulty ignition coil (s) - Engine Coil
  • Ignition coils harness is open or shorted
  • Ignition coils poor electrical connection
  • Clogged or faulty fuel injectors
  • Injectors harness is open or shorted
  • Injectors poor electrical connection
  • Improper spark plugs
  • Insufficient cylinders compression
  • Incorrect fuel pressure
  • Intake air leak
You can narrow down which cylinder the misfire is on if you pull a specific code. Ex. P0301 is cylinder #1, P0302 is cylinder #2, P0303 is Cylinder #3 and so on.
Internal Engine Diagram
divider
Top Categories

Serpentine Belt Routing Diagrams
Ask a Mechanic
Free Insurance Quotes
Car Owners Manuals
Auto Wiring Diagrams
Auto Repair Manuals
Auto Repair Estimates
Hybrid Cars
Nut & Bolt Measuring Charts
Mechanic's Lien Form

Manufacturer

Acura
Audi
BMW
Buick
Cadillac
Chevy
Chrysler
Datsun
Dodge
Ford
GEO
GMC


Honda
Hyundai
Infiniti
Isuzu
Jaguar
Jeep
Kia
Lexus
Lincoln
Mazda
Mercedes
Mercury


Mitsubishi
Nissan
Oldsmobile
Plymouth
Pontiac
SAAB
Saturn
Scion
Subaru
Suzuki
Toyota
VW
Top Repair

Air Conditioning Troubleshooting
Blown Head Gasket
Brakes
Auto Repair
Engine Overheating
Engine Sensors
Struts
Hub Bearings
No Start Diagnostics
Transmission