The 2022 Toyota 4Runner continues with Toyota's reliable 4.0L V6 engine producing 270 horsepower for capable off-road and on-road performance. When P0306: Cylinder 6 Misfire Detected appears, your 4Runner has identified that cylinder 6 isn't contributing properly to engine output.
Proven V6 Engine Architecture
The 4Runner's 1GR-FE 4.0L V6 represents Toyota's commitment to proven reliability. Cylinder 6 sits on the rear bank of the longitudinal engine. Unlike many competitors, this engine uses traditional port fuel injection, avoiding direct injection's carbon buildup complications while delivering straightforward maintenance.
Why Cylinder 6 Misfires Occur
Ignition coil degradation from thermal cycling affects the individual coil-on-plug units. Spark plugs nearing 100,000+ mile service intervals produce weak or erratic spark. Fuel injector flow restrictions from deposits or wear affect fuel delivery. Vacuum leaks create lean conditions specific to cylinder 6. Extended off-road idle time or low-speed operation can contribute to deposit formation.
Systematic Diagnosis
Retrieve all stored codes to understand the diagnostic picture. Access cylinder 6 on the rear bank—the 4Runner provides better access than many SUVs. Inspect the ignition coil for physical damage, cracks, or connector issues. Remove the spark plug and evaluate wear patterns and electrode condition. Test fuel injector pulse signal and spray pattern. Perform compression testing to verify mechanical integrity.
4Runner Longevity
The 4Runner V6 is known for exceptional durability. P0306 typically indicates routine maintenance items rather than serious problems. Quality repairs support the 4Runner's reputation for reaching extremely high mileage.