A P0302 code on your 2020 Toyota 4Runner indicates the engine control module detected repeated misfires in cylinder 2. The 4Runner's tried-and-true 4.0L 1GR-FE V6 is known for reliability, but individual cylinder misfires can still occur.
4Runner V6 Engine Layout
The 1GR-FE V6 positions cylinders 1-3-5 on the driver side and 2-4-6 on the passenger side. Cylinder 2 is the front cylinder on the passenger bank. This longitudinally-mounted engine provides reasonable access to cylinder 2 components from the top.
Common P0302 Causes
The 4.0L V6's common misfire causes include worn or fouled spark plugs, failed ignition coil, fuel injector issues, vacuum leaks, and rarely, mechanical problems. At 4+ years old, ignition component wear becomes more likely.
Off-Road Consideration
4Runners used off-road may experience additional issues. Water fording can introduce moisture to ignition components. Dust ingestion can affect sensors and filters. Check for signs of environmental contamination when diagnosing misfires on trail-used vehicles.
Systematic Diagnosis
Start with ignition component swap testing—move the cylinder 2 coil to another cylinder and monitor for misfire migration. Inspect the spark plug for fouling or wear. The 1GR-FE's port injection reduces carbon buildup concerns.