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 a sensor in your car that checks the pollution from the engine is not working as fast as it should. It's like when you ask a friend a question, and they take too long to answer.
The NOx sensor is responsible for measuring nitrogen oxide levels in the exhaust gases. This code indicates that the sensor is responding too slowly when it should be detecting lower levels of NOx.
The P22FA code is triggered when the Engine Control Module (ECM) detects that the NOx sensor on Bank 1 Sensor 1 is responding slower than expected during a transition from high to low NOx levels. This could be due to sensor degradation, contamination, or wiring issues.
• Check Engine Light is on
• Decreased fuel efficiency
• Poor engine performance
• Faulty NOx sensor
• Wiring issues or poor connection
• Exhaust leaks affecting sensor readings
NOx: Nitrogen Oxides, pollutants produced during combustion.
ECM: Engine Control Module, the computer that manages engine functions.
• Use an OBD-II scanner to confirm the code.
• Inspect the NOx sensor and its wiring for damage or disconnection.
• Check for exhaust leaks near the sensor.
• Replace the NOx sensor if faulty.
• Repair or replace damaged wiring or connectors.
• Fix any exhaust leaks.
• OBD-II scanner
• Multimeter
• Wrench set
$200 - $600
Moderate
• Volkswagen Jetta
• Audi A4
• BMW 3 Series
• Regularly inspect and maintain exhaust system components.
• Ensure timely replacement of sensors as per vehicle guidelines.
• Use high-quality fuel to prevent sensor contamination.
Sensor Issue
• Have your vehicle inspected by a professional if the Check Engine Light comes on.
• Avoid ignoring the issue as it may lead to more significant problems.
• Consider regular vehicle maintenance to prevent such issues.
Check your vehicle's warranty as emissions-related components may be covered.
This code has become more common with the increased use of NOx sensors in modern vehicles to meet emissions standards.
Moderate – While the vehicle may still be drivable, it is recommended to address this issue promptly to avoid emissions non-compliance and potential engine performance issues.
Driving with a malfunctioning NOx sensor may lead to increased emissions, which can be illegal in some areas and contribute to environmental pollution.
• Engine at operating temperature
• Vehicle driven under various load conditions
The NOx sensor is typically located in the exhaust system, upstream of the catalytic converter on Bank 1.
Q: What happens if I ignore the P22FA code?
A: Ignoring this code can lead to increased emissions, poor fuel economy, and potential damage to other engine components.
Q: Can I drive my car with a P22FA code?
A: While you may be able to drive, it is not recommended as it can lead to further issues and may be illegal due to emissions regulations.
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Fitment Required · Vehicle-fitment part
Relevant when catalyst-efficiency or emissions faults persist after proper diagnosis.
Catalyst-efficiency faults sometimes point toward converter problems after proper testing.
Catalytic converters are highly vehicle-specific and should not be purchased by code alone.
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.