Table of Contents
- 1. What Is a Cylinder 4 Misfire?
- 2. Signs of Cylinder 4 Trouble
- 3. Causes of Engine Misfire Issues
- 4. How Serious Is This Fault?
- 5. Diagnosing with iCarsoft Scanners
- 6. Steps to Fix Misfire Problems
- 7. Repair Costs in the U.S.
- 8. Tips to Prevent Future Misfires
- 9. Why Use iCarsoft for Diagnostics?
- 10. Common Questions About Misfires
- 11. Protect Your Engine from Misfires
1. What Is a Cylinder 4 Misfire?
Is your car shaking or losing power? You might have a P0304 Toyota issue, also known as a cylinder 4 misfire detected. This trouble code from the ignition system means cylinder 4 isn’t firing correctly, which can cause engine damage. Let’s explore what causes this cylinder misfiring and how to fix it with tools like the iCarsoft CR Eagle.
2. Signs of Cylinder 4 Trouble
This engine issue comes with clear signs you’ll notice:
- Check engine light appears on your dashboard
- Rough idling—your engine shakes or vibrates
- Weak acceleration due to reduced power
- Poor fuel economy from inefficient combustion
- Car stalls or hesitates occasionally
3. Causes of Engine Misfire Issues
Several factors can lead to this engine trouble code. Here’s what to look for:
- Faulty spark plugs or a faulty spark in cylinder 4
- A failing ignition coil or faulty ignition coils
- Fuel injector issues, such as clogs or leaks
- Low compression from a worn piston ring
- An unbalanced air fuel mixture due to vacuum leaks
- A faulty control module (ECM) sending incorrect signals
Each of these can affect cylinder 4’s performance, so a detailed check is essential.
4. How Serious Is This Fault?
This misfire issue is moderately serious. While you might still drive, it risks catalytic converter damage, higher emissions, and potential engine damage. Address it quickly to avoid bigger issues later.
5. Diagnosing with iCarsoft Scanners
An OBD II scanner like the iCarsoft CR Eagle or CR MAX makes diagnosing this fault simple. Here’s how:
- Connect the scanner to your car’s OBD-II port, often under the dashboard.
- Open the software and select your vehicle’s make and model.
- Read the error codes to confirm the cylinder 4 error.
- Monitor live data, like fuel injector or ignition coil performance.
- Clear the code after repairs to turn off the check engine light.
6. Steps to Fix Misfire Problems
Ready to resolve this engine issue? Here’s how to fix a cylinder misfiring problem:
- Replace faulty spark plugs or spark plug wire—a common cause.
- Test and swap out a bad ignition coil or coil pack if needed.
- Clean or replace the fuel injector for proper fuel flow.
- Check for a worn piston ring with a compression test.
- Fix vacuum leaks affecting the air fuel mixture.
- Reset or update the control module if it’s malfunctioning.
7. Repair Costs in the U.S.
Fixing this fault code in the U.S. usually costs $150–$600. Replacing a spark plug wire might be $50–$100, while a new coil pack could cost $100–$300. Labor rates vary by area. Note: Costs may differ outside the U.S.—check with your local mechanic.
8. Tips to Prevent Future Misfires
Keep this issue from returning with these steps:
- Replace spark plugs every 30,000 miles to avoid a faulty spark.
- Inspect ignition coils during tune-ups to catch issues early.
- Clean fuel injectors annually for a balanced air fuel mixture.
- Check piston rings with a compression test every 60,000 miles.
9. Why Use iCarsoft for Diagnostics?
The iCarsoft CR Eagle and CR MAX are ideal for handling error codes like this misfire issue. Here’s why:
- Compatible with most cars via OBD II.
- Reads live data to find problems quickly.
- User-friendly design for both DIYers and professionals.
- Clears codes fast to reset the check engine light.
10. Common Questions About Misfires
What is a cylinder 4 error?
This engine trouble code signals a misfire in cylinder 4, meaning it isn’t firing correctly. This can cause rough idling, reduced power, and potential engine damage if ignored.
How much does it cost to fix this issue?
In the U.S., fixing this fault typically costs $150–$600, depending on the problem (e.g., spark plug or ignition coil replacement). Costs may vary globally—check with your local mechanic.
11. Protect Your Engine from Misfires
This engine issue doesn’t have to spoil your drive. With tools like the iCarsoft CR Eagle, you can diagnose and fix a cylinder 4 error quickly. Regular maintenance helps avoid catalytic converter damage and other issues.
Dealing with other engine codes? Check our P0340 guide for more tips.
