p0300
Moderate
Toyota · Sedans
Random/Multiple Cylinder Misfire Detected
Quick Answer
Error code P0300 on your Toyota Sedans means: Random/Multiple Cylinder Misfire Detected. This is usually fixable — see the step-by-step guide below.
Affected Models
Likely Causes
  1. Worn or fouled spark plugs
  2. Defective ignition coils
  3. Low fuel pressure or clogged fuel injectors
  4. Vacuum leak causing lean condition
  5. Low engine compression in one or more cylinders
How to Fix It
1
Pull and inspect all spark plugs for wear, fouling, or incorrect gap
2
Test ignition coils individually by swapping between cylinders
3
Check fuel pressure and inspect injectors for blockage
4
Perform a vacuum leak test using smoke machine or carb cleaner
5
Run a compression test on all cylinders to rule out internal engine issues
Pro Tip
This fix requires some technical knowledge. If you're unsure about any step, consider contacting support or a qualified technician.
Parts You May Need
Spark plugs
Ignition coils
Fuel injectors
Intake manifold gasket
Related Error Codes
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