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Engine-Codes – Nissan – P0303 Nissan

P0303 Nissan Code - Number 3 Cylinder Misfire Detected

Quick Answer

When a P0303 code is triggered in a Nissan vehicle, it indicates that a misfire has been detected in the number 3 cylinder of the engine. Common causes include Faulty spark plug in the number 3 cylinder, Malfunctioning ignition coil that supplies spark to the cylinder, Clogged or dirty fuel injector affecting fuel delivery to the cylinder. 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
P0303 Nissan indicates Number 3 Cylinder Misfire Detected.
Common causes
Common causes include Faulty spark plug in the number 3 cylinder, Malfunctioning ignition coil that supplies spark to the cylinder, Clogged or dirty fuel injector affecting fuel delivery to the cylinder.
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.
What is this?
Table of contents Created and updated by William Orellana on Aug 19, 2024
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Code P0303 Nissan Description

When a P0303 code is triggered in a Nissan vehicle, it indicates that a misfire has been detected in the number 3 cylinder of the engine. This misfire can result from a variety of issues, such as a lack of spark, fuel, or compression in the cylinder. A misfire can lead to poor engine performance, reduced fuel efficiency, and potential damage to the catalytic converter over time. It is vital to address this issue promptly to prevent further damage to the engine.

OBDII Code P0303 Nissan - Number 3 Cylinder Misfire Detected
P0303 Nissan Code - Number 3 Cylinder Misfire Detected

Common Causes of P0303 Nissan

  1. Faulty spark plug in the number 3 cylinder.
  2. Malfunctioning ignition coil that supplies spark to the cylinder.
  3. Clogged or dirty fuel injector affecting fuel delivery to the cylinder.
  4. Low compression in the number 3 cylinder due to issues with the valves or piston rings.
  5. Vacuum leak impacting the air-fuel mixture in the cylinder.

Symptoms of P0303 Nissan

  1. Rough idling or vibrations felt while the vehicle is running.
  2. Loss of power or acceleration.
  3. Engine misfiring, which may manifest as a jerking sensation while driving.
  4. Decreased fuel efficiency.
  5. Illumination of the check engine light on the dashboard.

How to Fix P0303 Nissan

  1. Begin by diagnosing the specific cause of the misfire by conducting a thorough inspection of the spark plug, ignition coil, fuel injector, compression levels, and vacuum lines.
  2. Replace the faulty spark plug in the number 3 cylinder if it appears worn out or damaged.
  3. Test and potentially replace the ignition coil if it is not functioning correctly.
  4. Clean or replace the fuel injector if it is clogged or not delivering fuel properly.
  5. Address any compression issues in the number 3 cylinder by repairing or replacing faulty components.

Cost to Fix P0303 Nissan

The cost of repairing a P0303 code in a Nissan vehicle can vary depending on the specific cause of the misfire and the parts needed for the repair. On average, the repair cost for this issue can range from $100 to $500, including parts and labor. Keep in mind that diagnostic time and labor rates can vary, so it is recommended to obtain quotes from local auto repair shops for a more accurate estimate.

What does this mean?

Tech Notes for P0303 Nissan

The P0303 code means that cylinder #3 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 #3. 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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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 P0303 Nissan Code

1. What are the common symptoms of OBDII code P0303 (Nissan)?

- Common symptoms of OBDII code P0303 include engine misfires, rough idling, loss of power, and potential engine vibrations.

2. What are the possible causes of a number 3 cylinder misfire in a Nissan vehicle?

- Possible causes of a number 3 cylinder misfire in a Nissan vehicle may include faulty spark plugs, a defective ignition coil, a clogged fuel injector, vacuum leaks, or low compression in the cylinder.

3. How can I diagnose the source of the number 3 cylinder misfire in my Nissan?

- To diagnose the source of the number 3 cylinder misfire, you can perform a compression test, inspect the spark plugs and ignition coil, check for vacuum leaks, and use a scan tool to monitor live data while the engine is running.

4. What are some tips for repairing OBDII code P0303 in a Nissan?

- Some repair tips for OBDII code P0303 in a Nissan include replacing the spark plugs, inspecting and replacing the ignition coil if necessary, cleaning or replacing the fuel injector, checking for vacuum leaks, and performing a compression test.

5. Can driving with OBDII code P0303 (Nissan) cause further damage to the vehicle?

- Continuing to drive with OBDII code P0303 in a Nissan can potentially cause damage to the catalytic converter, oxygen sensors, and other engine components over time due to the unburned fuel entering the exhaust system.

6. Is it safe to ignore OBDII code P0303 (Nissan) and continue driving the vehicle?

- It is not recommended to ignore OBDII code P0303 in a Nissan as it can lead to poor engine performance, reduced fuel efficiency, and potential damage to other engine components. It is best to address the issue promptly.

7. How much does it typically cost to repair OBDII code P0303 in a Nissan?

- The cost to repair OBDII code P0303 in a Nissan can vary depending on the underlying cause of the misfire. Costs may include parts such as spark plugs, ignition coils, or fuel injectors, as well as labor charges if professional assistance is needed.

8. Can a DIY enthusiast fix OBDII code P0303 in a Nissan at home?

- Depending on the cause of the misfire, a DIY enthusiast with the necessary tools and knowledge may be able to address OBDII code P0303 in a Nissan at home by replacing spark plugs, inspecting ignition components, and checking for vacuum leaks.

9. How important is it to address OBDII code P0303 promptly in a Nissan?

- Addressing OBDII code P0303 promptly in a Nissan is important to prevent potential engine damage, ensure optimal performance, maintain fuel efficiency, and avoid more costly repairs in the future.

10. Can extreme weather conditions or poor fuel quality trigger OBDII code P0303 in a Nissan?

- Extreme weather conditions or poor fuel quality can sometimes contribute to the occurrence of OBDII code P0303 in a Nissan by affecting the combustion process in the engine. It is important to use quality fuel and maintain the vehicle properly to reduce the risk of misfires.

Discuss the causes and fixes for P0303 Nissan OBDII Code

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  • How to fix Cylinder Misfire on 2007-2012 Nissan Altima:

    https://youtu.be/pP0I-iSBUF4

    Reply to Comment

  • So I had people tell me that it was the crankshaft sensor but after replacing it it made no difference so I went back to basic automotive trouble shooting I changed the plugs is a pain but if you do it it's free. After the plug I checked the injectors cleaned them with cleaner and a piece of wire cut with a nice point. Don't forget after removing the intake manifold to replace the gasket. You should be satisfied by this point if still problems most likely you need to replace a coil pack or single... if still no luck bank 2 crankshaft sensor is probably bad possibly even bank 2 ...bank 1 will throw a p0345. .....me I got plugs and manifold gasket and one coil and was good to go

    Other than this I have done
    Alternator
    Radiator
    Wheel bearing
    Control arms
    Tie rods and sway bars
    Strut tower
    Cv boots
    Plugs
    All before 150,000 when I did most of it at 50.000 it's crazy how much goes wrong and how this car is not cheap to fix

    Reply to Comment