What does code P0300 mean on a Lexus and is it safe to drive?
P0300: Random/Multiple Cylinder Misfire Detected. Here's what it means on your Lexus, 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 Lexus
- 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 Lexus, 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 Lexus
Lexus P0300 on 3.5L 2GR-FE V6 engines is uncommon before 120k miles. When it occurs, inspect coil-on-plug boots—the rubber boots degrade and allow moisture to short the coils in plug wells. On 2GR-FSE direct-injection engines (IS350, GS350), carbon buildup on intake valves combined with D4-S direct injection causes lean misfires. Lexus recommends walnut blasting at 80k+ intervals on FSE engines. On GX470 4.7L 2UZ-FE V8, P0300 is uncommon and usually indicates a failing ignition coil or spark plug in an inaccessible rear cylinder.
Most commonly affected models