Engine-CodesInfiniti – P0303 Infiniti

P0303 Infiniti Code - Number 3 Cylinder Misfire Detected

Quick Answer

The P0303 code for Infiniti vehicles specifically indicates that a misfire has been detected in the number 3 cylinder of the engine. Common causes include Faulty spark plugs, Malfunctioning ignition coil, Clogged fuel injector. 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 Infiniti indicates Number 3 Cylinder Misfire Detected.
Common causes
Common causes include Faulty spark plugs, Malfunctioning ignition coil, Clogged fuel injector.
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.
Table of contents Created and updated by William Orellana on Sep 08, 2024
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Code P0303 Infiniti Description

The P0303 code for Infiniti vehicles specifically indicates that a misfire has been detected in the number 3 cylinder of the engine. When a misfire occurs, it means that the cylinder is not firing properly, which can result in a lack of power, rough idling, and decreased fuel efficiency. In the case of the number 3 cylinder misfire, it points to a specific cylinder within the engine that is not functioning as it should.

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

Common Causes of P0303 Infiniti

  1. Faulty spark plugs
  2. Malfunctioning ignition coil
  3. Clogged fuel injector
  4. Vacuum leaks
  5. Engine compression issues

Symptoms of P0303 Infiniti

  1. Rough idling
  2. Loss of power
  3. Decreased fuel efficiency
  4. Engine stalling
  5. Illuminated check engine light

How to Fix P0303 Infiniti

  1. Diagnose the specific cause of the misfire by performing a comprehensive engine check and inspecting the spark plugs, ignition coil, fuel injector, and vacuum lines.
  2. Replace the faulty spark plugs if they are worn or damaged.
  3. Test the ignition coil for proper functioning and replace if necessary.
  4. Clean or replace the clogged fuel injector.
  5. Check for vacuum leaks and repair or replace any damaged lines.

Cost to Fix P0303 Infiniti

The typical repair costs for addressing a P0303 code on an Infiniti vehicle can range from $100 to $500, depending on the specific cause of the misfire and the extent of the repairs needed. This estimate includes parts and labor, but it is important to note that prices can vary based on the location of the auto repair shop, the vehicle's make and model, and the type of engine. It is recommended to obtain a detailed quote from a trusted mechanic before proceeding with the repair.

Tech Notes for P0303 Infiniti

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 Infiniti 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.

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