Engine-Codes.com
Engine-Codes – Hyundai – P0306 Hyundai

P0306 Hyundai Code - Cylinder 6 Misfire Detected

Quick Answer

When a P0306 code is triggered in a Hyundai vehicle, it indicates that a misfire has been detected in cylinder 6 of the engine. Common causes include Faulty ignition system (spark plugs, ignition coils), Fuel delivery issues (clogged fuel injector, low fuel pressure), Vacuum leaks. 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
P0306 Hyundai indicates Cylinder 6 Misfire Detected.
Common causes
Common causes include Faulty ignition system (spark plugs, ignition coils), Fuel delivery issues (clogged fuel injector, low fuel pressure), Vacuum leaks.
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
💬 Need more help? Ask Auto Expert for instant answers — it's free!
AutoCodes App

Fix Your Car Smarter

Try the New AutoCodes App!

Get complete OBDII diagnostics, repair solutions, and cost estimates, plus AI chat support on demand.

AutoCodes App on Google Play

Code P0306 Hyundai Description

When a P0306 code is triggered in a Hyundai vehicle, it indicates that a misfire has been detected in cylinder 6 of the engine. This misfire can lead to a rough idle, decreased engine performance, and potentially even engine stalling. The misfire occurs when there is an incomplete combustion process in the cylinder, which can be caused by issues such as a lack of spark, fuel, or compression. If not addressed, a misfiring cylinder can cause damage to the engine over time and lead to more serious issues.

OBDII Code P0306 Hyundai - Cylinder 6 Misfire Detected
P0306 Hyundai Code - Cylinder 6 Misfire Detected

Common Causes of P0306 Hyundai

  1. Faulty ignition system (spark plugs, ignition coils)
  2. Fuel delivery issues (clogged fuel injector, low fuel pressure)
  3. Vacuum leaks
  4. Compression problems (valve issues, piston ring wear)
  5. Engine timing problems

Symptoms of P0306 Hyundai

  1. Rough idle
  2. Loss of power
  3. Engine vibration
  4. Increased fuel consumption
  5. Engine stalling

How to Fix P0306 Hyundai

  1. Diagnose the specific cause of the misfire by checking the ignition system, fuel delivery system, vacuum lines, and compression.
  2. Replace faulty spark plugs and ignition coils if necessary.
  3. Clean or replace clogged fuel injectors and check fuel pressure.
  4. Check for vacuum leaks and repair or replace any damaged components.
  5. Address any compression issues by inspecting valves, piston rings, and timing components.

Cost to Fix P0306 Hyundai

The cost of repairing a cylinder 6 misfire in a Hyundai can vary depending on the specific cause of the issue. On average, the repair could range from $100 to $500, including parts and labor. It's important to note that diagnostic time and labor rates at auto repair shops can vary, so it's recommended to get a few quotes from different shops to determine the most cost-effective option.

What does this mean?

Tech Notes for P0306 Hyundai

The P0306 code means that the cylinder 6 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 6. If the problem persists more tests needs to be done to diagnose problem, see "Possible Causes"

When is the Code Detected?

Engine Cylinder 6 is Misfiring.

Need more information about the P0306 Hyundai code?

Need more information on how to fix the P0306 Hyundai code? Get Access to Factory Service Manuals

Need Help with the Code?

Get the P0306 Hyundai code diagnosed by a professional: Find a repair shop in your area

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 P0306 Hyundai Code

1. What are the common symptoms of OBDII code P0306 in a Hyundai, indicating Cylinder 6 misfire detected?

- Common symptoms include rough idling, loss of power, engine vibration, and potential hesitation or jerking during acceleration.

2. What are some possible causes of OBDII code P0306 in a Hyundai?

- Potential causes include faulty ignition coil, worn spark plugs, clogged fuel injector, vacuum leaks, low compression in cylinder 6, or issues with the engine control module.

3. How can I diagnose the specific cause of the Cylinder 6 misfire in my Hyundai triggering code P0306?

- Diagnostic steps may involve inspecting and testing the ignition coil, spark plugs, fuel injector, compression levels in cylinder 6, checking for vacuum leaks, and scanning the engine control module for error codes.

4. Are there any DIY repair tips for addressing OBDII code P0306 in a Hyundai related to Cylinder 6 misfire?

- DIY repair tips may include replacing the faulty ignition coil or spark plugs, cleaning or replacing the clogged fuel injector, performing a compression test on cylinder 6, and checking for vacuum leaks.

5. Can driving with OBDII code P0306 indicating Cylinder 6 misfire harm my Hyundai's engine?

- Continuing to drive with a misfire can potentially lead to damage to the catalytic converter, reduced fuel efficiency, and further engine issues if left unresolved for an extended period.

6. How urgent is it to address OBDII code P0306 related to Cylinder 6 misfire in a Hyundai?

- It is recommended to address the issue promptly to prevent potential damage to the engine components and ensure optimal performance and fuel efficiency of the vehicle.

7. Is it necessary to reset the OBDII code P0306 after repairing the Cylinder 6 misfire issue in a Hyundai?

- It is advisable to clear the error code using an OBDII scanner after addressing the misfire problem to reset the Check Engine Light and monitor if the issue has been resolved.

8. Can extreme weather conditions contribute to triggering OBDII code P0306 in a Hyundai due to Cylinder 6 misfire?

- Extreme temperatures or humidity can sometimes exacerbate existing issues leading to a Cylinder 6 misfire, so it is essential to ensure proper maintenance and address any underlying problems.

9. What role does regular maintenance play in preventing OBDII code P0306 related to Cylinder 6 misfire in a Hyundai?

- Regular maintenance, including timely spark plug replacements, ignition system checks, and fuel injector cleanings, can help prevent issues that may trigger a misfire in cylinder 6 and the associated OBDII code.

10. Are there any recalls or service bulletins related to OBDII code P0306 and Cylinder 6 misfire in Hyundai vehicles?

- It is advisable to check with Hyundai dealership or official sources for any recalls or service bulletins related to this specific issue to ensure proper identification and resolution of the problem.

Discuss the causes and fixes for P0306 Hyundai OBDII Code

Submit a New Comment

  • 2006 hyundai sonata 6 cyl 3.3 engine

    Replaced intake manifold gaskets, and all six plugs, and O2 sensors (both upstream). Cleared codes, drove for about 4 or 5 miles, all is well. Got to 75 mph, and the check engine light came on & immediately started flashing. Codes show random cylinder misfire, misfire on cylinder 3, misfire on cylinder 6. Swapped ignition coils on cylinders 4 & 6, cleared codes, & drove. Flashing CE light again. Codes still identify cylinders 3 and 6, eliminating the coil as the cause. MAP is showing 8 inHg.
    Suggestions? How do I test manifold for leak, and would that cause these symptoms? No codes appear other than misfires.
    Thanks
    Sandy

    Reply to Comment