What usually causes it
- Worn spark plugs
- Weak ignition coils or old spark plug wires
- A vacuum leak or a dirty air flow sensor
- Weak fuel delivery, like a clogged filter or a failing pump
- Low engine compression or a timing problem
P0300Starts at: Get it checked this week
Engine is misfiring in more than one cylinder
More than one cylinder, the chambers where fuel burns, is misfiring, or the computer cannot tell which one. A misfire means a cylinder is not burning its fuel the right way.
Check this first
Think about when the spark plugs were last changed. Old plugs are the most common cause, and new ones are a low cost fix on many cars.
What to watch for
- A flashing check engine light means a bad misfire. Stop driving as soon as you safely can
- Shaking, stumbling or weak power
- A rotten egg smell, because raw fuel can harm the catalytic converter, the exhaust part that cleans the fumes
Can I keep driving?
We rate P0300 as Get it checked this week. It is not an emergency yet, but it can get worse. If the light starts flashing, stop driving soon.
Quick answers about P0300
What does P0300 mean?
Engine is misfiring in more than one cylinder. More than one cylinder, the chambers where fuel burns, is misfiring, or the computer cannot tell which one. A misfire means a cylinder is not burning its fuel the right way.
Can I keep driving with P0300?
We rate P0300 as Get it checked this week. It is not an emergency yet, but it can get worse. If the light starts flashing, stop driving soon.
What usually causes P0300?
The most common causes, in order: Worn spark plugs; Weak ignition coils or old spark plug wires; A vacuum leak or a dirty air flow sensor; Weak fuel delivery, like a clogged filter or a failing pump; Low engine compression or a timing problem.
Estimates only. A mechanic should confirm. The same code can mean slightly different things on different cars; the app explains it for your exact year, make, model and mileage.