What does code P0300 mean on a Alfa Romeo and is it safe to drive?
P0300: Random/Multiple Cylinder Misfire Detected. Here's what it means on your Alfa Romeo, what usually causes it, what repairs typically cost, and how safe it is 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 for your 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 Alfa Romeo, repairs for P0300 often fall between $150 and $1200, depending on the cause and whether you use OEM or aftermarket parts. Labor rates vary by location.
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