When your 2020 Nissan Frontier triggers the P0304 code, the engine control module has detected recurring misfires in cylinder 4. As one of the final years of the long-running second-generation Frontier, this mid-size truck's proven V6 engine benefits from extensive service experience and well-documented diagnostic procedures.
Understanding P0304 in the 2020 Frontier
The 2020 Frontier features the 3.8L V6 engine producing 310 horsepower—an upgrade from earlier model years. This V6 configuration positions cylinder 4 on the rear bank. Nissan V6 engines typically number cylinders 2, 4, 6 on the rear bank and 1, 3, 5 on the front bank. The engine management system identifies cylinder 4 misfires through crankshaft velocity analysis.
Truck Engine Misfire Causes
The naturally aspirated V6 faces standard ignition wear patterns. Work truck use including towing and hauling may accelerate component wear compared to lighter-duty applications. Spark plug electrode erosion occurs normally over time. Ignition coils degrade from heat cycling. Fuel injector spray patterns affect combustion quality in all operating conditions.
Diagnostic Process
Retrieve all codes and note freeze frame conditions when misfires occurred. Access the rear bank for cylinder 4 inspection—the truck's engine bay typically provides reasonable access. Test spark plug and ignition coil condition. Verify fuel injector operation. Consider the truck's usage patterns when evaluating wear.
Repair Solutions
Install Nissan-approved spark plugs for the 3.8L V6. Replace ignition coils showing degraded output. Address fuel system concerns as identified. Trucks with heavy-duty use may benefit from shortened maintenance intervals.