What P0304 means
Cylinder 4 Misfire Detected
Common causes (general)
Before spending money on parts, verify the code with a scan tool and read freeze frame data. Freeze frame captures every sensor value at the moment the code set — this is often enough to figure out the root cause without further testing.
Manufacturer-specific descriptions
Different manufacturers use this code for slightly different failure modes. Here's what your specific make means by P0304:
| AUDI | Worn out spark plugs, ignition wires, coil(s), distributor cap and rotor (when applicable), Incorrect ignition timing, Vacuum leak(s), Low or weak fuel pressure, Improperly functioning EGR system, Defective Mass Air Flow Sensor, Defective Crankshaft and or Camshaft Sensor, Defective Throttle Position Sensor, Mechanical engine problems (i.e.—low compression, leaking head gasket(s), or valve problem... |
| BMW | Cylinder 4 Misfire Detected |
| FORD | Cylinder #4 Misfire Detected |
| HONDA | No. 4 Cylinder Misfire |
| MITSUBISHI | Cylinder 4 Misfire Detected; No.4 cylinder misfire detected |
| NISSAN | Cylinder 4 Misfire Detected |
| VOLKSWAGEN | Cylinder 4 Misfire Detected |
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