AutoCodes – Nissan – P0304 2008 Nissan Sentra

P0304 2008 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 2008 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.

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Code Popularity 5,084

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
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Code P0304 2008 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 2008 Nissan Sentra - Number 4 Cylinder Misfire Detected - AutoCodes.com — P0304 2008 Nissan Sentra Code - Number 4 Cylinder Misfire Detected

What does this mean?

What are the Possible Causes of the DTC P0304 2008 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 2008 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 2008 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 2008 Nissan Sentra code?

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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 2008 Nissan Sentra Code

1. What are the common symptoms of OBDII code P0304 in a 2008 Nissan Sentra?

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

2. What are the possible causes of a Number 4 cylinder misfire in a 2008 Nissan Sentra?

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

3. How can I diagnose the Number 4 cylinder misfire in my 2008 Nissan Sentra?

- Diagnose the issue by checking the spark plugs, ignition coils, fuel injectors, vacuum lines, and performing a compression test on the engine.

4. Can a dirty fuel injector cause OBDII code P0304 in a 2008 Nissan Sentra?

- Yes, a dirty or clogged fuel injector can lead to a misfire in the Number 4 cylinder, triggering OBDII code P0304.

5. How can I repair a Number 4 cylinder misfire in my 2008 Nissan Sentra?

- Repair options include replacing faulty spark plugs, ignition coils, or fuel injectors, fixing vacuum leaks, and addressing any compression issues.

6. Is it safe to continue driving my 2008 Nissan Sentra with OBDII code P0304?

- It is not recommended to drive with a misfiring cylinder as it can cause damage to the engine and other components. It's best to address the issue promptly.

7. Will resetting the OBDII code P0304 in my 2008 Nissan Sentra solve the problem?

- Resetting the code may temporarily turn off the check engine light, but it will not fix the underlying issue causing the Number 4 cylinder misfire.

8. Can a bad ignition coil cause OBDII code P0304 in a 2008 Nissan Sentra?

- Yes, a faulty ignition coil can lead to a misfire in the Number 4 cylinder, triggering the OBDII code P0304.

9. How much does it typically cost to repair OBDII code P0304 in a 2008 Nissan Sentra?

- The repair costs for OBDII code P0304 can vary depending on the exact cause of the misfire, but expect to pay for parts and labor for component replacement or repairs.

10. Are there any preventive maintenance tips to avoid OBDII code P0304 in a 2008 Nissan Sentra?

- Regularly servicing your vehicle, including changing spark plugs and maintaining ignition components, can help prevent cylinder misfires and OBDII codes like P0304.