If your 2024 Toyota 4Runner is displaying a P0305 code indicating a cylinder 5 misfire, this requires careful diagnostic investigation. The 2024 model year represents a complete redesign of the 4Runner, which now uses a 2.4-liter turbocharged four-cylinder engine (T24A-FTS) instead of the previous V6. A four-cylinder engine only has cylinders numbered 1 through 4, making a P0305 code technically anomalous.
Understanding the 2024 4Runner Engine Change
The sixth-generation 2024 Toyota 4Runner transitioned to Toyota's TNGA-F platform and replaced the 4.0L V6 with either the 2.4L turbocharged four-cylinder producing 278 horsepower or the i-FORCE MAX hybrid system that pairs the same four-cylinder with an electric motor. Neither configuration has a cylinder 5, so a legitimate P0305 code cannot occur on this vehicle.
Why P0305 May Appear
When P0305 appears on a four-cylinder engine, several explanations exist. ECM programming or calibration issues could cause incorrect code storage. An aftermarket scan tool or code reader may have misinterpreted data. Previous codes from another vehicle may have been inadvertently transferred during diagnostic equipment use. Internal ECM faults, though rare, can also produce erroneous codes.
Recommended Diagnostic Approach
Use a Toyota-compatible professional scan tool to verify the stored code and review freeze frame data. Check if any actual misfire symptoms exist such as rough running, hesitation, or reduced power. If the engine runs normally, the code may be erroneous. Clear the code and monitor for recurrence. If genuine misfire symptoms exist, investigate cylinders 1-4 using standard misfire diagnostic procedures.
Important Considerations
If you recently purchased this vehicle or had it serviced elsewhere, confirm the VIN matches the scan tool's vehicle identification. The 2024 4Runner's new platform may also have software updates available that address early production ECM calibration issues.