When your 2024 Subaru Impreza displays the P0304 code, the engine control module has detected recurring misfires in cylinder 4. The completely redesigned sixth-generation Impreza features updated boxer engines requiring understanding of Subaru's distinctive horizontally-opposed design for effective diagnosis.
Understanding P0304 in the 2024 Impreza
The redesigned 2024 Impreza offers the 2.0L FB20 boxer four-cylinder in base models or the more powerful 2.5L FB25 in RS trim. Both horizontally-opposed configurations position cylinder 4 at the rear of the left (driver's) bank. This unique engine layout affects accessibility and service approach.
New Platform Considerations
First-year redesigned vehicles may reveal unexpected issues as miles accumulate. The 2024 Impreza now features hatchback-only body styles with updated engine bay layout. Standard ignition and fuel causes remain the most common P0304 sources. Monitor for technical service bulletins.
Diagnostic Methodology
Identify your engine size—2.0L or 2.5L. Use a scanner current with 2024 Impreza calibrations. Locate cylinder 4 on the left bank rear position. Test ignition coil output and spark plug condition. Verify fuel injector operation.
Repair Solutions
Install Subaru-specified spark plugs for your engine type. Clean spark plug wells before removal. Replace degraded ignition coils. Address fuel system concerns. New vehicle warranty should cover manufacturing defects.