When your 2020 Nissan Frontier displays the P0305 code, the engine control module has detected repeated misfires in cylinder 5. The 2020 Frontier uses the 3.8L V6 engine (replacing the previous 4.0L), which has six cylinders numbered 1-6, making P0305 a legitimate diagnostic code.
2020 Frontier Powertrain
The 2020 Frontier received a significant powertrain update with the new 3.8L V6 producing 310 horsepower, replacing the long-running 4.0L V6. This newer engine is paired with a 9-speed automatic transmission. No four-cylinder option exists for the Frontier.
Cylinder 5 Location
On Nissan's V6, cylinder 5 is positioned on the rear bank toward the firewall. In the Frontier's longitudinal engine mounting, the rear bank is toward the firewall, making cylinder 5 somewhat challenging to access.
Common Causes
At 2020 mileage levels, spark plug wear is possible if maintenance has been deferred. Ignition coil failure can occur individually. Fuel injector issues may cause lean misfires. Vacuum leaks around the intake affect specific cylinder performance. Check for any rodent damage to wiring, which is common on trucks parked outdoors.
Diagnostic Process
Read all codes and freeze frame data. Inspect cylinder 5's spark plug for wear or fouling. Test the ignition coil. Check for vacuum leaks. Inspect wiring harnesses for damage. Verify fuel injector operation.