What does code P0300 mean on a Chevrolet and is it safe to drive?
P0300: Random/Multiple Cylinder Misfire Detected. Here's what it means on your Chevrolet, what usually causes it, what repairs typically cost, and how safe it is to keep driving.
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 Chevrolet
- 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 Chevrolet, 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 Chevrolet
Chevrolet P0300 on 5.3L LS V8 is critically linked to AFM (Active Fuel Management) lifter collapse—when an AFM lifter fails, that cylinder goes dead and the ECU may not isolate it to a single cylinder code, instead logging P0300. If you see P0300 with a lifter tick on a 5.3L, the AFM lifter assembly needs to be replaced. On Equinox and Malibu 2.4L Ecotec, P0300 following P0171 (lean) is the progression—the lean condition causes misfires. Check the valve cover PCV diaphragm first.
Most commonly affected models