The P0304 code in your 2020 Nissan Pathfinder indicates the engine control module has detected persistent misfires in cylinder 4. The Pathfinder's 3.5L V6 engine requires understanding of V6 cylinder configuration for effective diagnosis and repair of this combustion problem.
Understanding P0304 in the 2020 Pathfinder
The 2020 Pathfinder features Nissan's 3.5L V6 producing 284 horsepower through variable valve timing. This V6 configuration positions cylinder 4 on the rear bank—the bank closest to the firewall. Nissan V6 engines typically number cylinders 1, 3, 5 on the front bank and 2, 4, 6 on the rear bank. The engine management system identifies cylinder 4 through crankshaft velocity pattern analysis.
V6 Misfire Causes
The naturally aspirated 3.5L V6 faces standard ignition wear patterns including spark plug electrode erosion from high-output operation. Ignition coils degrade over time from heat cycling. Direct fuel injection contributes to intake valve carbon accumulation. The rear bank's location makes components less accessible but also subjects them to different thermal conditions than front bank cylinders.
Diagnostic Approach
Retrieve all codes and analyze freeze frame data. Access the rear cylinder bank where cylinder 4 is located—the Pathfinder's engine bay layout may require removing intake components for full access. Test spark plug and ignition coil condition. Verify fuel injector operation. Consider carbon buildup inspection for higher-mileage vehicles.
Repair Solutions
Install Nissan-specified spark plugs for the 3.5L V6. Replace ignition coils showing degraded output. Address fuel system concerns. Professional carbon cleaning benefits vehicles showing carbon accumulation symptoms.