Easy one-page printout for the garage or repair shop
This summary uses the existing diagnostic information shown in full below.
This code means that the car's computer has detected that the air and fuel mixture in cylinder 2 is not right. There's too much air and not enough fuel, which can make the engine run poorly.
The engine control module (ECM) monitors the air-fuel ratio for each cylinder. If it detects that the mixture in cylinder 2 is too lean (more air than fuel), it triggers the P11D2 code.
The P11D2 code indicates that the air-fuel ratio in cylinder 2 is imbalanced, specifically too lean. This can be caused by issues such as a vacuum leak, a faulty fuel injector, or a problem with the mass air flow sensor. The ECM uses data from the oxygen sensors to determine the air-fuel ratio and adjusts the fuel injection accordingly. If the adjustments exceed a certain threshold, the code is set.
• Check engine light on
• Rough idle
• Poor fuel economy
• Vacuum leak near cylinder 2
• Faulty fuel injector for cylinder 2
• Mass air flow sensor malfunction
ECM: Engine Control Module, the computer that controls the engine's functions
Air-Fuel Ratio: The ratio of air to fuel in the engine's combustion chamber
• Check for vacuum leaks around cylinder 2
• Inspect and test the fuel injector for cylinder 2
• Test the mass air flow sensor
• Repair any vacuum leaks found
• Replace or clean the fuel injector for cylinder 2
• Replace the mass air flow sensor if faulty
• OBD-II scanner
• Vacuum gauge
• Fuel injector tester
$150 - $500
Moderate
• Honda Accord
• Toyota Camry
• Ford Focus
• Regularly inspect for vacuum leaks
• Use quality fuel
• Regular maintenance of fuel injectors
Engine Performance
• Avoid driving aggressively until the issue is fixed
• Monitor fuel economy for sudden changes
Check with the vehicle manufacturer for warranty coverage on engine components.
This code has been reported in vehicles with over 100,000 miles more frequently, often due to wear and tear on fuel system components.
Moderate – It should be addressed soon to avoid potential engine damage.
Ignoring this code may lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle at idle
Cylinder 2 is typically located on the engine block, often identified in the vehicle's service manual.
Q: Can I drive with a P11D2 code?
A: It's possible to drive short distances, but it's recommended to fix the issue soon to prevent engine damage.
Q: Will a P11D2 code affect my car's performance?
A: Yes, it can cause poor fuel economy and rough idling.
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Useful if diagnosis points toward damaged connectors, wiring, or terminal repairs.
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Fitment Required · Vehicle-fitment part
Relevant when the code or supporting diagnostics point toward upstream or downstream oxygen-sensor faults.
This code family often involves upstream or downstream oxygen-sensor diagnosis.
Verify exact sensor position and vehicle fitment before buying.
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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.