When your 2020 Toyota Tundra displays the P0304 code, the engine control module has identified consistent misfires in cylinder 4. The second-generation Tundra uses proven V8 engines.
2020 Tundra Engine Options
The 2020 Tundra offers the 4.6L 1UR-FE V8 (310 hp) or 5.7L 3UR-FE V8 (381 hp). Both use port fuel injection. Cylinder 4 is on the driver's side (left) bank on these V8 engines.
Common Causes
- Ignition Coil Failure: Individual coil-on-plug failures
- Spark Plug Wear: V8 engines have eight plugs to maintain
- Fuel Injector Problems: Port injection deposits
- Vacuum Leaks: Intake manifold or gasket issues
- Air Injection System: Secondary air system concerns
Diagnostic Approach
Use a Toyota-compatible scanner for V8 diagnostics. Port injection is simpler than direct injection. Monitor misfire counts across all eight cylinders. Test ignition components.
Repair Solutions
Replace failed ignition coils with Denso OEM components. Install Toyota-specified spark plugs. Clean fuel injectors if needed. Repair vacuum leaks.