Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This means that the car's computer has detected that the air and fuel mixture in cylinder 4 is not right. It's getting too much air and not enough fuel, which can cause problems with how the engine runs.
The engine control module (ECM) monitors the air-fuel ratio for each cylinder. Code P11D6 indicates that the air-fuel mixture in cylinder 4 is too lean, meaning there's more air than fuel compared to the ideal ratio.
The air-fuel ratio imbalance for cylinder 4 is detected when the ECM determines that the mixture is too lean. This can be due to issues such as a malfunctioning fuel injector, vacuum leaks, or faulty sensors. The lean condition can lead to poor engine performance and increased emissions.
• Check engine light is on
• Poor engine performance
• Rough idle
• Increased fuel consumption
• Engine misfires
• Faulty fuel injector in cylinder 4
• Vacuum leak near cylinder 4
• Faulty mass air flow (MAF) sensor
• Clogged fuel filter
• Exhaust gas recirculation (EGR) issues
ECM: Engine Control Module
MAF Sensor: Mass Air Flow Sensor
EGR: Exhaust Gas Recirculation
• Use an OBD-II scanner to confirm the code.
• Inspect the fuel injector for cylinder 4 for clogs or malfunctions.
• Check for vacuum leaks around cylinder 4.
• Test the mass air flow sensor for proper operation.
• Inspect the fuel filter for clogs.
• Clean or replace the fuel injector for cylinder 4.
• Repair any vacuum leaks found.
• Replace or clean the mass air flow sensor.
• Replace the fuel filter if clogged.
• Check and repair the EGR system if necessary.
• OBD-II scanner
• Fuel injector cleaner or replacement
• Vacuum leak detector
• Multimeter
• Basic hand tools
$150 - $500
Moderate
• Honda Accord
• Toyota Camry
• Ford F-150
• Regular maintenance of fuel injectors.
• Periodic checks for vacuum leaks.
• Regularly replace air and fuel filters.
Engine Performance
• Avoid driving with this code active for extended periods.
• Regularly maintain your vehicle to prevent such issues.
• Consult a professional mechanic if unsure about repairs.
Check your vehicle's warranty for coverage on engine components.
This code has been associated with fuel system issues and is commonly seen in vehicles with high mileage.
Moderate – While not immediately dangerous, it can lead to more serious engine problems if not addressed.
Driving with a lean condition may lead to increased emissions, which can be illegal in some areas.
• Engine at operating temperature
• Vehicle idling
Cylinder 4 is typically located on the engine block, depending on the engine layout.
Q: Can I drive my car with a P11D6 code?
A: It's possible to drive short distances, but it's not recommended to ignore the issue as it can lead to more severe engine problems.
Q: How can I prevent a P11D6 code?
A: Regular maintenance, including checking for vacuum leaks and keeping fuel injectors clean, can help prevent this code.
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Fitment Required · Vehicle-fitment part
Commonly relevant for misfire, ignition-efficiency, and some drivability-related repairs.
Misfire and ignition-related faults commonly involve spark plugs as part of the repair path.
Check the correct plug type, gap, and engine application for your vehicle.
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Fitment Required · Vehicle-fitment part
Relevant when the fault points toward ignition-coil performance or cylinder-specific ignition issues.
Some ignition faults involve coil performance or cylinder-specific coil problems.
Match the coil to your engine and confirm the failed component before ordering.
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Fitment Required · Vehicle-fitment part
Relevant for airflow, fuel-trim, and intake-metering faults after confirming the sensor is actually at fault.
Airflow and fuel-trim codes can involve the mass air flow sensor after proper diagnosis.
Verify the sensor design and fitment for your exact vehicle.
View options on AmazonThese parts may be related to this fault category, but a code by itself does not confirm exact fitment or guarantee that replacing a part will solve the problem.