2018 Alfa Romeo P0300: What It Means & Is It Safe to Drive?
P0300 on the 2018 Alfa Romeo: Random/Multiple Cylinder Misfire Detected. Here's what it means, what usually causes it, what repairs typically cost, and whether it's safe to keep driving.
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What this code means
The PCM has detected misfires across multiple cylinders. This can cause damage to the catalytic converter if driven for long.
Common causes on the 2018 Alfa Romeo
- Worn spark plugs or ignition coils
- Clogged or bad fuel injectors
- Low compression
- Vacuum leak, bad MAF, or fuel delivery issue
Symptoms
- Check Engine Light (often flashing under load)
- Rough idle, shaking, loss of power
- Possible smell of unburned fuel
Typical fixes
- Replace spark plugs and coils as needed
- Clean or replace fuel injectors
- Fix vacuum/fuel issues
- Compression test if no obvious cause
Repair cost range
For a 2018 Alfa Romeo, repairs for P0300 typically fall between $150 and $1200, depending on the root cause and labor rates in your area.
Known issues on Alfa Romeo
Alfa Romeo Giulia and Stelvio P0300 on the 2.0L turbocharged inline-4 can be caused by a failing fuel injector or ignition coil. Carbon buildup on GDI intake valves is also a documented cause on higher-mileage units.
Most commonly affected models
Giulia 2017–2022Stelvio 2018–2022