P0304
Cylinder 4 Misfire Detected
P0304 is an OBD-II diagnostic trouble code meaning: Cylinder 4 Misfire Detected. Common causes: faulty spark plugs, problems with the ignition coil. Estimated repair cost: $56–167.
Symptoms
- The engine hesitates or runs unevenly
- Power Loss
- Increased fuel consumption
- Vibration at idle
- Check Engine light comes on
Causes
- Faulty spark plugs
- Problems with the ignition coil
- Clogged fuel injectors
- Low cylinder compression
- Problems with sensors (mass air flow sensor, oxygen sensor)
- Vacuum leak
- Ignition system malfunction
How to Fix
- Check spark plugs in cylinder 4
- Check ignition coil and wires
- Check the fuel injector of cylinder 4
- Measure the compression in the cylinder
- Check the intake manifold for leaks
- Read additional error codes to determine the cause
Related codes
Error P0304 by Vehicle Brand
FAQ
What does the P0304 code mean?
P0304 is an OBD-II diagnostic trouble code that indicates: Cylinder 4 Misfire Detected
What causes a P0304 error code?
The most common causes of P0304 include: Faulty spark plugs; Problems with the ignition coil; Clogged fuel injectors; Low cylinder compression.
How do I fix a P0304 diagnostic trouble code?
To fix P0304: Check spark plugs in cylinder 4. Check ignition coil and wires. Check the fuel injector of cylinder 4. For a complete diagnosis, use an OBD-II scanner.
Is it safe to drive with P0304?
Limited driving only, diagnose soon
How much does it cost to fix P0304?
The estimated repair cost for P0304 is $56–167. Actual cost depends on your vehicle, location, and labor rates.
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