P0300 Toyota Tundra
Random/Multiple Cylinder Misfire Detected · Powertrain Code · High · Repair: Moderate
What is P0300?
The ECM has detected misfires occurring in multiple or random cylinders. Common causes include worn spark plugs, faulty ignition coils, vacuum leaks, low fuel pressure, or a failing catalytic converter.
When the Toyota Tundra triggers code P0300 (random/multiple cylinder misfire detected), it typically points to an issue in the powertrain system. This is a high severity code, so address it promptly to avoid further damage or safety concerns. Below you'll find the most common causes, symptoms, and repair options specific to the Toyota Tundra.
This repair is rated moderate, meaning some experience and specialty tools required.
Diagnostic data on this page is compiled from publicly available repair resources and technical service bulletins. Always have a qualified mechanic confirm the diagnosis before authorizing repairs on your Toyota Tundra.
Common Causes on Toyota Tundra
- Ignition coil failure on 3.5L V6 twin-turbo in Tundra or 2.4L turbo in Tacoma (2024+)
- Spark plug electrode erosion from towing and heavy load use on 3.5L V6
- Secondary air injection system failure causing rich condition and catalyst damage on older 4.0L V6
- Carbon buildup on intake valves from direct injection on 2.4L turbo iForce (Tacoma 2024+)
- Vacuum leak at intake manifold gasket from thermal cycling on 3.5L V6 4Runner
Symptoms
- Rough idle with noticeable engine vibration
- Engine shaking or stumbling under load
- Loss of power during acceleration
- Check engine light flashing intermittently
- Poor fuel economy
- Hesitation or stumble on acceleration
Notes for Toyota Tundra
The new 2.4L turbo iForce in the 2024+ Tacoma is a pure GDI engine more susceptible to carbon buildup.