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AutoCodes – Toyota – P0306 Toyota

P0306 Toyota Code - Cylinder 6 Misfire Detected

Quick Answer

When the engine misfires, high concentrations of Hydrocarbons (HC) enter the exhaust gas. Common causes include Intake air leak, Faulty spark plug #6, Faulty ignition coil #6. 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 Toyota indicates Cylinder 6 Misfire Detected.
Common causes
Common causes include Intake air leak, Faulty spark plug #6, Faulty ignition coil #6.
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.
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Code Popularity 51,017
How popular is this code, among other codes? Medium
What is this?
Table of contents Created and updated by William Orellana on Aug 25, 2022
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Code P0306 Toyota Description

When the engine misfires, high concentrations of Hydrocarbons (HC) enter the exhaust gas. Extremely high hydrocarbon concentration levels can cause an increase in exhaust emission levels. Extremely high concentrations of hydrocarbons can also cause increases in the three-way catalytic converter temperature, which may cause damage to the three-way catalytic converter. To prevent this increase in emissions and to limit the possibility of thermal damage, the Engine Control Module (ECM) monitors the misfire count. When the temperature of the three-way catalytic converter reaches the point of thermal degradation, the ECM blinks the MIL. To monitor misfires, the ECM uses both the camshaft position sensor and the crankshaft position sensor. The camshaft position sensor is used to identify any misfiring cylinders and the crankshaft position sensor is used to measure variations in the crankshaft rotation speed. Misfires are counted when the crankshaft rotation speed variations exceed predetermined thresholds. If the misfire count exceeds the threshold levels and could cause emission control system performance deterioration, the ECM illuminates the MIL and stores a Diagnostic Trouble Code (DTC).
OBDII Code P0306 Toyota - Cylinder 6 Misfire Detected - AutoCodes.com
P0306 Toyota Code - Cylinder 6 Misfire Detected
What does this mean?

What are the Possible Causes of the DTC P0306 Toyota?

  • Intake air leak
  • Faulty spark plug #6
  • Faulty ignition coil #6
  • Clogged or faulty fuel injector #6
  • Fuel injectors #6 harness is open or shorted
  • Fuel Injectors #6 circuit poor electrical connection
  • Ignition coils #6 harness is open or shorted
  • Ignition coils #6 circuit poor electrical connection
  • Incorrect Fuel pressure
  • Faulty Mass Air Flow (MAF) Sensor
  • Faulty Engine Control Module (ECM)
  • Faulty Engine Coolant Temperature (ECT) Sensor

How to Fix the DTC P0306 Toyota?

Review the 'Possible Causes' above and visually examine the corresponding wiring harness and connectors. Check for damaged components and inspect connector pins for signs of being broken, bent, pushed out, or corroded.

What does this mean?

Code Tech Notes

The P0306 code means that 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 need to be done to diagnose the problem. See "Possible Causes" for the most common problems.

What is the Cost to Diagnose the Code?

Labor: 1.0

To diagnose the P0306 Toyota code, it typically requires 1.0 hour of labor. Rates vary by location, vehicle, and shop. Many shops charge between $80–$150 per hour; dealerships and metro areas may be higher, independents may be lower.

Need more information about the P0306 Toyota code?

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Information for Specific Toyota 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.

Frequently Asked Questions about P0306 Toyota Code

1. What are common symptoms of OBDII code P0306 in a Toyota indicating Cylinder 6 Misfire Detected?

Symptoms may include rough idling, loss of power, engine vibration, and an illuminated check engine light.

2. What are some possible causes of a Cylinder 6 misfire in a Toyota triggering code P0306?

Potential causes include faulty spark plugs, ignition coils, fuel injectors, vacuum leaks, low compression, or issues with the engine control module.

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

Diagnosis typically involves checking spark plugs, ignition coils, fuel injectors, compression levels, vacuum leaks, and conducting a thorough inspection of the engine components.

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

DIY repair tips may include replacing spark plugs, ignition coils, or fuel injectors, as well as checking and repairing any vacuum leaks or addressing issues with the engine control module.

5. Can driving with a misfire related to code P0306 in Cylinder 6 of a Toyota cause further damage?

Continued driving with a misfire can potentially damage the catalytic converter, oxygen sensors, or other engine components, and may lead to reduced fuel efficiency and performance.

6. How important is it to address OBDII code P0306 indicating a Cylinder 6 misfire in a Toyota promptly?

It is crucial to address the issue promptly to prevent further damage to the engine, ensure optimal performance, and maintain fuel efficiency.

7. What is the average cost to repair a Cylinder 6 misfire in a Toyota triggering OBDII code P0306?

The repair cost can vary depending on the specific cause of the misfire, but it may range from a few hundred to over a thousand dollars when considering parts and labor.

8. Can a Cylinder 6 misfire related to OBDII code P0306 be intermittent or occur only under specific conditions in a Toyota?

Yes, misfires can be intermittent and may occur only under certain conditions such as during acceleration, at idle, or when the engine is cold.

9. Is it advisable to clear the OBDII code P0306 related to Cylinder 6 misfire in a Toyota after making repairs?

Yes, it is recommended to clear the code after repairs are made to see if the issue has been successfully resolved and to ensure the check engine light does not reappear.

10. How can regular maintenance help prevent Cylinder 6 misfires and OBDII code P0306 in a Toyota?

Regular maintenance such as timely spark plug replacements, fuel system cleanings, and engine inspections can help prevent misfires and related issues, including code P0306.

Discuss the causes and fixes for P0306 Toyota OBDII Code

Submit a New Comment

  • see what I got on camry Toyota 2005 Cylinder 6 misfire detected

    Reply to Comment

  • Gud day all I have change the coil, sparkplug and injector still is still showing cyclnder 6 misfire what next can I do pls ?

    Reply to Comment

  • The next step is to perform a compression or leak down test. You may have a blown head gasket.

    Reply to Comment

  • Tnx for ur reply, I took out the front cylinder and notice that the piston has a clearance the cylinder 6. So what the next step to follow ?

    Reply to Comment
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