P0304
Cylinder 4 Misfire Detected
System: Ignition
Severity: medium
What does P0304 mean?
The DTC P0304 (Cylinder 4 Misfire Detected) is a fault code stored by the ECU when it detects a misfire cyl 4 condition in the ignition subsystem. It is commonly seen on European and Asian vehicles using Bosch, Continental, Siemens or Denso ECUs.
Common causes of P0304
- Coil/plug cyl 4
- Injector
- Low compression
- Head gasket
How to fix P0304
Component-swap diagnosis. Always compression-test if swap doesn't move the misfire.
Tuning approach with DaVinci Deluxe · Cloud Edition
For P0304, DaVinci Deluxe · Cloud Edition offers the following ECU map adjustments and software solutions:
- Per-cylinder fuel trim
- Spark advance per cyl
Need to fix P0304 on your ECU?
DaVinci Deluxe · Cloud Edition is professional ECU tuning software trusted by 800+ workshops. 24-Hour Pass €45.99, 10 minutes free trial.
See pricing Try free