P0305 Cylinder 4 Misfire Detected

If your car is showing signs of a rough running engine or reduced power, you may have encountered a P0305 code, which indicates a cylinder 4 misfire. This engine code can be a cause for concern, but don’t worry, we’ve got you covered.

In this article, we will discuss the causes of a cylinder 4 misfire, symptoms to look out for, and the steps you can take to fix it. So, let’s dive in!

What Causes a Cylinder 4 Misfire?

A cylinder 4 misfire can occur due to several reasons, including:

  1. Faulty Ignition System: A faulty ignition system can cause a misfire in one or more cylinders. This can be due to a failed spark plug, coil or distributor.
  2. Fuel System Issues: Issues with the fuel system, such as a clogged fuel injector, can also cause a cylinder 4 misfire.
  3. Mechanical Issues: Mechanical issues such as a worn-out camshaft or crankshaft, or a damaged valve spring, can also cause a misfire.

Symptoms of a Cylinder 4 Misfire

The symptoms of a cylinder 4 misfire can vary, but the most common ones are:

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  1. Rough Running Engine: A misfire can cause the engine to run roughly or unevenly.
  2. Reduced Power: A misfire can also cause a reduction in engine power, leading to slower acceleration and poor performance.
  3. Engine Light: The check engine light may turn on, indicating a problem with the engine.

Steps to Fix a Cylinder 4 Misfire

Here are the steps you can take to fix a cylinder 4 misfire:

Step 1: Check the Ignition System

The first step is to check the ignition system. Start by inspecting the spark plug, ignition coil, and distributor. Replace any faulty components.

Step 2: Check the Fuel System

Next, check the fuel system. Use a fuel injector cleaner to clean any dirt or debris that may be clogging the fuel injector.

Step 3: Check for Mechanical Issues

If the misfire persists, check for any mechanical issues. Inspect the camshaft, crankshaft, and valve springs for any damage or wear. If you find any issues, replace the damaged parts.


A cylinder 4 misfire can cause several issues with your car’s performance. However, with the right diagnosis and repair, you can fix the problem and get your car running smoothly again. Remember to always address engine issues as soon as possible to avoid further damage and costly repairs.


Q1. Can a cylinder 4 misfire cause engine damage?

A. Yes, a cylinder 4 misfire can cause engine damage if left unchecked.

Q2. How do I know if my car is misfiring?

A. Look out for signs such as a rough running engine, reduced power, and the check engine light turning on.

Q3. Can a clogged fuel injector cause a cylinder 4 misfire?

A. Yes, a clogged fuel injector can cause a cylinder 4 misfire.

Q4. Is it safe to drive with a cylinder 4 misfire?

A. It is not recommended to drive with a cylinder 4 misfire as it can cause damage to the engine.

Q5. How much does it cost to fix a cylinder 4 misfire?

A. The cost varies depending on the cause of the misfire, but it can range from $100 to $1,000.