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P0304 Nissan Code - Number 4 Cylinder Misfire Detected

Quick Answer

When a misfire occurs, engine speed will fluctuate. Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4. Severity is High - diagnose this code as soon as possible. Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.

What it means
P0304 Nissan indicates Number 4 Cylinder Misfire Detected.
Common causes
Common causes include Faulty Spark Plug #4, Clogged or faulty Fuel Injector #4, Faulty Ignition Coil #4.
Severity
High - diagnose this code as soon as possible.
Can I drive?
Driving is not recommended if the warning light is flashing, the engine runs poorly, or safety-related symptoms are present.
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Code Popularity 105,675
How popular is this code, among other codes? Medium
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Table of contents Created and updated by William Orellana on Aug 09, 2022
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Code P0304 Nissan Description

When a misfire occurs, engine speed will fluctuate. If the engine speed fluctuates enough to cause the Crankshaft Position (CKP) sensor signal to vary, the Engine Control Module (ECM) can determine that a misfire is occurring. The Diagnostic Trouble Code (DTC) will be set when the Engine Control Module monitors the crankshaft speed and has detected that engine cylinder #4 is misfiring.
OBDII Code P0304 Nissan - Number 4 Cylinder Misfire Detected - AutoCodes.com
P0304 Nissan Code - Number 4 Cylinder Misfire Detected
What does this mean?

What are the Possible Causes of the DTC P0304 Nissan?

  • Faulty Spark Plug #4
  • Clogged or faulty Fuel Injector #4
  • Faulty Ignition Coil #4
  • Fuel Injector #4 harness is open or shorted
  • Fuel Injector #4 circuit poor electrical connection
  • Ignition Coil #4 harness is open or shorted
  • Ignition Coil #4 circuit poor electrical connection
  • Insufficient cylinder 4 compression
  • Incorrect fuel pressure
  • Intake air leak

How to Fix the DTC P0304 Nissan?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0304 code means that cylinder #4 is misfiring or is randomly misfiring. Start by checking for intake leaks and if no leaks are found the next step is to replace the spark plugs on cylinder #4. If the problem persists more tests need to be done to diagnose the problem. See "Possible Causes" for the most common problems.





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What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0304 Nissan code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

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Information for Specific Nissan Models

About the author: William Orellana is a Master Mechanic and Mechanical Engineer with over 30 years of experience diagnosing and repairing vehicles. Learn more about his background.

Frequently Asked Questions about P0304 Nissan Code

1. What does the OBDII code P0304 mean on a Nissan?

P0304 indicates a misfire in cylinder number 4, meaning the engine isn't properly combusting fuel in that cylinder.

2. What are the common symptoms of a P0304 code in a Nissan?

Symptoms include rough idling, decreased engine performance, poor fuel economy, and sometimes a flashing check engine light.

3. What causes a P0304 code in a Nissan?

Common causes include a faulty spark plug, bad ignition coil, clogged fuel injector, vacuum leak, or low cylinder compression.

4. Can I drive my Nissan with a P0304 code?

Driving with a P0304 code is not recommended, as it can cause further engine damage, such as catalytic converter failure.

5. How do I fix a P0304 code on my Nissan?

Start by inspecting and replacing the spark plug or ignition coil for cylinder 4. If the issue persists, check the fuel injector, vacuum leaks, or perform a compression test.

6. How can I identify cylinder number 4 on my Nissan engine?

Cylinder numbering varies by engine type, but typically, cylinder 4 is the fourth in the firing order or layout specified in the service manual.

7. Can a dirty air filter cause a P0304 code on a Nissan?

A dirty air filter is unlikely to cause a single-cylinder misfire like P0304, but it can contribute to overall engine performance issues.

8. Will a P0304 code cause long-term damage to my Nissan?

If not addressed, a P0304 code can lead to engine damage, increased emissions, and possible failure of expensive components like the catalytic converter.

9. How much does it cost to fix a P0304 code on a Nissan?

Repair costs vary based on the cause, ranging from $50 for a spark plug replacement to $500 or more for diagnosing and fixing complex issues like injector or compression problems.

10. Can a bad fuel injector cause a P0304 code in a Nissan?

Yes, a clogged or leaking fuel injector in cylinder 4 can disrupt fuel delivery and cause a misfire, triggering the P0304 code.

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