Code P0301 means a misfire on cylinder number 1. Unlike P0300 the cause is local: spark plug, coil, injector or compression of that cylinder.
What code P0301 means
Misfire on cylinder 1.
Typical symptoms
- Rough idle and vibration
- Jerking and loss of power
- Check engine light on or flashing
- Smell of unburned fuel
- Higher fuel consumption
Most likely causes
| Cause | How common | What to do |
|---|---|---|
| Worn spark plug on cylinder 1 | Very common | Replace the plugs |
| Coil or lead of cylinder 1 | Common | Swap test and replace |
| Injector of cylinder 1 | Common | Test and replace |
| Low compression in cylinder 1 | Less common | Compression test |
| Local air leak, wiring | Less common | Check and repair |
How it is diagnosed
- Read misfire counters.
- Swap coil and plug with another cylinder: if the code moves, it is that component.
- Injector test.
- Compression test.
Can you drive with code P0301?
With a steady light yes, with care; if it flashes, stop to avoid damaging the catalytic converter.
How much does it cost to fix?
| Work | Indicative cost |
|---|---|
| Spark plug | €10-40 each |
| Coil | €40-150 |
| Injector | €150-400 |
| Mechanical repair | on quote |
Figures are indicative market ranges, useful for orientation: the real cost depends on model, engine, parts chosen and labour hours. For an exact quote we need the vehicle registration number.
How MasterTuning helps
We read the real values of the control unit, not just the code: that is the difference between finding the faulty component and replacing parts by trial and error. After the repair we clear the error and check that it does not come back. Find the nearest centre or contact us.
Got code P0301 on your car? Book a diagnosis at the nearest MasterTuning centre.
Frequently asked questions
What does P0301 mean?
Misfire on cylinder 1.
How do you find the cause?
By swapping coil or plug with another cylinder: if the code moves (e.g. P0302), the component is the culprit.
Is P0301 serious?
If the light flashes yes, because of the risk to the catalytic converter; otherwise it should be fixed soon anyway.
How much does it cost to fix P0301?
From €10-40 for a spark plug to €150-400 for an injector.
