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 thinks too much air is going into the engine on one side because it got a weird reading from a sensor that checks the air and fuel mix.
The engine control module (ECM) is detecting a higher than expected air flow reading from the oxygen sensor on Bank 2, indicating a potential issue with air intake or sensor functionality.
P111C is triggered when the ECM receives a signal from the oxygen sensor on Bank 2 that suggests the mass or volume air flow is higher than the expected range. This can be due to a malfunctioning sensor, air leak, or other intake issues.
• Check engine light on
• Poor fuel economy
• Rough idling
• Faulty oxygen sensor
• Air intake leak
• Mass air flow sensor malfunction
ECM: Engine Control Module
Oxygen Sensor: A device that measures the oxygen level in the exhaust gases
• Scan for codes and freeze frame data
• Inspect oxygen sensor and wiring
• Check for air leaks in intake system
• Replace faulty oxygen sensor
• Repair or replace damaged intake hoses
• Clean or replace mass air flow sensor
• OBD-II scanner
• Multimeter
• Wrench set
$150 - $400
Moderate
• Toyota Camry
• Ford F-150
• Honda Accord
• Regularly inspect air intake system
• Replace air filters as recommended
• Use high-quality fuel
Engine Performance
• Avoid hard acceleration until fixed
• Monitor fuel consumption
• Get a professional diagnostic
Check with your vehicle manufacturer for emissions-related warranty coverage.
This code is often associated with air intake issues or sensor malfunctions in vehicles with higher mileage.
Moderate – It should be addressed soon to prevent further engine performance issues.
Driving with a malfunctioning sensor can lead to increased emissions and potential engine damage.
• Engine at operating temperature
• Vehicle in closed-loop mode
The oxygen sensor for Bank 2 is located on the exhaust manifold of the engine side opposite to Bank 1.
Q: Can I drive with a P111C code?
A: It's not recommended to drive for extended periods as it may lead to poor performance and increased emissions.
Q: How do I know if my oxygen sensor is bad?
A: Symptoms include poor fuel economy, rough idling, and a check engine light.
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Universal · Digital multimeter
A solid entry-level multimeter for voltage, continuity, resistance, and basic electrical troubleshooting.
Helpful for checking voltage drops, grounds, and basic circuit health when modules are not communicating.
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Universal · Wire connectors and repair kit
Useful when diagnosis points toward damaged wiring, corroded terminals, or connector repairs.
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.