1. Home
  2. /
  3. Complete List of OBD2...
  4. /
  5. P0311 Code – What...

P0311 Code – What Does It Mean & How To Fix It

This is one of the most frequent OBD2 trouble codes. Read the full article below to know what it means, how to fix it, and what other codes may show related to it.


Understanding Diagnostic Trouble Codes (DTC) is crucial for maintaining your vehicle’s performance. One such code that can be seen on the dashboard is P0311. In this comprehensive guide, we will assess the definition, meaning, causes, symptoms, diagnosis, common mistakes, and possible remedies for P031e. Let us first look at what P0311 means.


To fully grasp P0311, let’s break down its meaning:

  • “P” stands for Powertrain, indicating that the issue affects the engine and transmission.

  • “0” denotes a generic code that applies to all vehicle makes and models.

  • “3” specifies that it’s a misfire code.

  • “11” identifies the specific cylinder where the misfire is detected, in this case, cylinder number 11.

In essence, P0311 informs you that there’s a misfire occurring in the eleventh cylinder of your engine.


Now, let’s explore the common causes behind P0311:

  • Ignition System Issues: Problems with the ignition system, such as a faulty spark plug or ignition coil, can lead to misfires in a specific cylinder.
  • Fuel Delivery Problems: Insufficient fuel delivery to cylinder 11 can result in a misfire.
  • Vacuum Leaks: Leaks in the intake manifold or vacuum lines can disrupt the air-fuel mixture, leading to misfires.
  • Sensor Malfunctions: Faulty sensors, such as the Mass Airflow Sensor (MAF) or the Crankshaft Position Sensor, can provide incorrect data to the engine control module, causing misfires.


P0311-related problems can show up in many different ways, including:

  • Check Engine Light: The check engine light on your dashboard turning on is the most typical sign.
  • Rough Idling: If you see your car idling roughly, it often means there was a cylinder misfire.
  • Reduced Power: Engine misfires may significantly lower the power and overall performance of an engine.
  • Increased Emissions: Prolonged misfires can result in higher emissions, which may affect your vehicle’s compliance with emissions standards.


It’s critical to use a methodical diagnostic approach when dealing with a P0311 code:

  • Code Scan: Start by retrieving the code and learning its specifics using an OBD-II scanner.
  • Visual Inspection: Look for wear or damage on the spark plugs and ignition coils that are part of the ignition system.
  • Check the fuel system: Make sure that the fuel delivery system is operating properly by testing the fuel pressure and injectors.
  • Sensor evaluation: Check the accuracy of important sensors, such as the MAF sensor or the crankshaft position sensor.

Common mistakes

Some frequent errors to avoid when diagnosing and fixing P0311 are as follows:

  • Misfires can result from neglecting basic maintenance, which includes changing spark plugs at the proper intervals.
  • Replacing components without doing enough testing could result in time and financial waste.
  • Ignoring other relevant codes or problems, since misfires may occasionally be a sign of deeper difficulties.

How serious is this?

The root cause and the degree of the misfire are two elements that affect how bad a P0311 code is. Even though there is no immediate danger, ignoring this code might eventually result in decreased engine performance, higher emissions, and even damage to the catalytic converter. It is advised to diagnose and fix problems right away to avoid developing new ones.

What repairs can fix the codeS?

repair manuals

The repairs needed to address P0311 will depend on the specific cause but may include:

  • Replacing faulty spark plugs or ignition coils.
  • Addressing fuel delivery issues, such as clogged fuel injectors or a failing fuel pump.
  • Fixing vacuum leaks in the intake system.
  • Replacing malfunctioning sensors that contribute to the misfire.

Related codes

P0311 may be associated with other related codes, such as:

  • P0300: “Random/Multiple Cylinder Misfire Detected,” which indicates misfires occurring in multiple cylinders.
  • P0301, P0302, P0303, etc.: These codes specify misfires in individual cylinders, with the last digit indicating the cylinder number (e.g., P0301 for cylinder 1 misfire).


P0311 is a diagnostic error code that indicates a failure in a specific cylinder of your engine, in this case, cylinder 11. It is crucial to understand what this means, its causes, symptoms, and diagnosis processes for the issue to be adequately addressed. It may help restore the performance of your vehicle and avoid possible damage if it is promptly diagnosed and repaired accordingly. If you encounter a P0311 code, it’s advisable to consult a qualified mechanic to ensure a proper diagnosis and resolution, keeping your vehicle running smoothly.

P0311 Code – What Does It Mean & How To Fix It