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 noticed that too much fuel is being sent to one side of the engine when the car is working hard.
The engine control module (ECM) has detected that the air-fuel mixture is too rich (too much fuel) in Bank 2 during high load conditions.
The P21FF code indicates that the ECM has found an imbalance in the air-fuel ratio on Bank 2 of the engine, specifically that the mixture is too rich when the engine is under higher load conditions. This could be due to a malfunction in the fuel delivery system, such as a faulty fuel injector or a problem with the mass airflow sensor.
• Check Engine Light is on
• Poor fuel economy
• Engine runs rough or stalls
• Faulty fuel injector
• Mass airflow sensor malfunction
• Fuel pressure regulator issue
ECM: Engine Control Module
MAF: Mass Airflow Sensor
• Use an OBD-II scanner to confirm the code.
• Inspect fuel injectors for leaks or clogs.
• Check the mass airflow sensor for proper operation.
• Replace or clean faulty fuel injectors.
• Repair or replace the mass airflow sensor.
• Adjust or replace the fuel pressure regulator.
• OBD-II scanner
• Fuel pressure gauge
• Multimeter
$150 - $500
Moderate
• Toyota Camry
• Ford F-150
• Chevrolet Silverado
• Regular maintenance of fuel system components
• Use quality fuel
• Periodically check and clean sensors
Engine Performance
• Do not ignore the Check Engine Light.
• Get the vehicle inspected by a professional.
• Avoid driving under heavy loads until fixed.
Check with your vehicle manufacturer for specific warranty coverage related to emissions and engine components.
This code has been associated with vehicles that have fuel system issues due to age or poor maintenance.
Moderate – Should be addressed soon to prevent further engine issues.
Driving with a rich fuel mixture can lead to increased emissions and potential damage to the catalytic converter.
• Engine at operating temperature
• Vehicle under load conditions
Bank 2 refers to the side of the engine opposite Bank 1, typically where cylinders 2, 4, 6, etc., are located.
Q: What does 'too rich' mean?
A: It means there is too much fuel and not enough air in the engine's air-fuel mixture.
Q: Can I drive with a P21FF code?
A: It's not recommended to drive for long periods with this code as it can lead to further engine damage.
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