Error code

OBD2 P0304

OBD2P0304
Diagnostic Trouble Code· Standard OBD-II fault code read from the vehicle's onboard diagnostics.

What it means

Cylinder 4 Misfire Detected.

Severity

moderateCan drive, but performance will be affected and it may cause further engine damage if not addressed.

Summary

P0304 indicates that cylinder 4 in the engine is misfiring. This issue can be detected by the PCM using signals from the crankshaft and camshaft position sensors.

Symptoms

  • Engine shaking or rough idling
  • Decreased fuel efficiency

Common Causes

  • Faulty spark plug in cylinder 4
  • Defective ignition coil for cylinder 4
  • Wiring issues related to cylinder 4
  • Malfunctioning fuel injector in cylinder 4

Diagnosis

  1. Check the spark plug for cylinder 4
  2. Inspect the ignition coil for cylinder 4
  3. Examine wiring connections related to cylinder 4
  4. Test the fuel injector in cylinder 4

Fixes

  • Replace faulty spark plug, ignition coil, or fuel injector as needed.

FAQ

What should I do if my car has a P0304 code?

You should diagnose the issue by checking the spark plug, ignition coil, wiring, and fuel injector for cylinder 4. If any of these components are faulty, they need to be replaced.

View source

Not affiliated with OBD2. Answer summarized from the manufacturer's manual linked above; consult that source for the authoritative procedure.

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