Check the DTC code with the KDS (Refer to "DTC guide").

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Check the connection condition of the ignition coil connector (A).
[Bank 1]

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[Bank 2]

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Check the installation condition of the ignition coil (A).
Tightening torque:

9.8 - 11.7 N.m (1.0 - 1.2 kgf.m, 7.2 - 8.7 lb.ft)

[Bank 1]

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[Bank 2]

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Remove the spark plug.
(Refer to Spark Plug - "REMOVAL AND INSTALLATION ")

Visual inspection of the spark plugs.

Spark plug gap [mm (in.)]: 1.0 - 1.1 (0.0394 - 0.0433.)

Symptom	Suspected Cause	Correction
Courtesy of KIA MOTORS AMERICA, INC. Melting electrode	Abnormal combustion, overheat	Replace the spark plugs
Courtesy of KIA MOTORS AMERICA, INC.	Carbon and foreign matter
Courtesy of KIA MOTORS AMERICA, INC. Ring crack	Abnormal combustion, external shock
Courtesy of KIA MOTORS AMERICA, INC. Vertical crack	External shock
Courtesy of KIA MOTORS AMERICA, INC. Overheat	Abnormal combustion

Symptom	Suspected Cause	Correction
Courtesy of KIA MOTORS AMERICA, INC. Poor gap	Physical damage	Replace the spark plugs
Courtesy of KIA MOTORS AMERICA, INC. Flash over	Excessive electrode wear	Replace the spark plugs, ignition coil
Courtesy of KIA MOTORS AMERICA, INC. Corrosion/Rust	Remaining oil mist	Reassemble the spark plugs

Check the resistance between the spark plugs terminal (A) and probe (B) by using a multi-tester or a resistance meter.
Specification: 2 - 20 KΩ (Room temperature)

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NOTE:
- Avoid the contact resistance between probe and spark plugs (when it occurs, the measured value is not stabilized).
- Be careful not to damage center electrode (A) while measuring resistance.
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Test for changing position of each ignition coil.
1. Remove the spark plug and ignition coil from the misfiring cylinder and exchange them with one of the other cylinders.
  (Refer to Spark Plug - "REMOVAL AND INSTALLATION ")
2. Replace the spark plugs, if misfire moves along the spark plugs.

When to See a Mechanic

Stop DIY work and contact a certified mechanic immediately if any of the following apply:

• You smell fuel, burning insulation, or see smoke.

• Brakes feel soft, pull hard to one side, or make grinding noises.

• The engine overheats, stalls repeatedly, or misfires under load.

• You are missing required tools, torque specs, or safe lifting equipment.

• You are not confident in the next step or safety outcome.

Safety Warning

Spark Plug: Troubleshooting