AutoCodes – Nissan – P0304 2009 Nissan Sentra

P0304 2009 Nissan Sentra 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 2009 Nissan Sentra 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.

Save to My Repairs Step-by-Step Diagnostic Guide My Repairs

AI answers can be wrong. Verify repairs with testing. Open full chat

Code Popularity 6,972

How popular is this code, among other codes? Low

Repair Importance Level

Urgent (Diagnose now) (3 / 3)

Repair Difficulty Level

Advanced (Pro) (3 / 3)

What is this?

Table of contents Created and updated by William Orellana on Aug 09, 2022

Description
Step-by-Step Diagnostic Guide
Possible Causes
How To Fix
Tech Notes
Cost to Diagnose
FAQs
Comments
Add Comment

💬 Need more help? Ask Coddy for instant answers — it's free!

Code P0304 2009 Nissan Sentra 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 2009 Nissan Sentra - Number 4 Cylinder Misfire Detected - AutoCodes.com — P0304 2009 Nissan Sentra Code - Number 4 Cylinder Misfire Detected

What does this mean?

What are the Possible Causes of the DTC P0304 2009 Nissan Sentra?

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 2009 Nissan Sentra?

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.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0304 2009 Nissan Sentra 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.

Need more information about the P0304 2009 Nissan Sentra code?

Need more information on how to fix the P0304 2009 Nissan Sentra code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0304 2009 Nissan Sentra code diagnosed by a professional: Find a repair shop in your area

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 2009 Nissan Sentra Code

1. What are common symptoms of OBDII code P0304 on a 2009 Nissan Sentra?

- Common symptoms include engine misfiring, rough idling, loss of power, and potential stalling.

2. What are the possible causes of a number 4 cylinder misfire detected in a 2009 Nissan Sentra?

- Common causes may include faulty spark plugs, ignition coils, fuel injectors, vacuum leaks, or a problem with the engine's compression.

3. How can I diagnose the cause of a P0304 code on my 2009 Nissan Sentra?

- Diagnosing the issue may involve checking the spark plugs, ignition coils, fuel injectors, vacuum lines, and performing a compression test to pinpoint the exact cause.

4. Can a dirty or clogged fuel injector cause a P0304 code on a 2009 Nissan Sentra?

- Yes, a dirty or clogged fuel injector can disrupt the fuel delivery to the number 4 cylinder, leading to a misfire and triggering the P0304 code.

5. Is it safe to drive my 2009 Nissan Sentra with a P0304 code?

- It is not recommended to drive your vehicle with a misfire as it can cause further damage to the engine and reduce fuel efficiency. It is best to address the issue promptly.

6. How much does it typically cost to repair a P0304 code on a 2009 Nissan Sentra?

- The cost of repair can vary depending on the underlying cause of the misfire, but it may range from a simple spark plug replacement to more extensive repairs involving ignition components or engine issues.

7. Can I reset the OBDII code P0304 on my 2009 Nissan Sentra without fixing the underlying issue?

- While you can clear the code temporarily, it is not recommended as the underlying issue causing the misfire will persist and could lead to more severe problems down the line.

8. Are there any maintenance tips to prevent a P0304 code on a 2009 Nissan Sentra?

- Regular maintenance, such as replacing spark plugs and ignition components at recommended intervals, keeping up with oil changes, and using quality fuel, can help prevent issues that may trigger a misfire.

9. Can a bad coil pack cause a P0304 code on a 2009 Nissan Sentra?

- Yes, a faulty ignition coil pack can lead to a misfire in the number 4 cylinder, triggering the P0304 code on your Nissan Sentra.

10. How long does it typically take to repair a P0304 code on a 2009 Nissan Sentra?

- The repair time can vary depending on the exact cause of the misfire and the extent of the repairs needed. Simple fixes like replacing spark plugs may take less time compared to diagnosing and fixing more complex issues.