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 system thinks the filter for cleaning exhaust gases is not working hard enough on one side of the engine.
The P14B6 code indicates that the flow resistance in the particle filter on Bank 2 is lower than expected, suggesting a potential issue with the filter's ability to trap soot particles.
The Diesel Particulate Filter (DPF) is designed to capture and store exhaust soot to reduce emissions. The P14B6 code is triggered when the Engine Control Module (ECM) detects that the flow resistance through the DPF on Bank 2 is lower than the threshold, indicating a possible leak, damage, or malfunction in the filter or its sensors.
• Check Engine Light is on
• Decreased fuel efficiency
• Increased exhaust smoke
• Possible engine performance issues
• Leak in the exhaust system
• Faulty differential pressure sensor
• Damaged or missing DPF
• Faulty ECM
DPF: Diesel Particulate Filter, a device designed to remove diesel particulate matter or soot from the exhaust gas of a diesel engine.
ECM: Engine Control Module, the computer that controls the engine's functions.
• Inspect the exhaust system for leaks or damage.
• Check the differential pressure sensor for proper operation.
• Verify the integrity of the DPF.
• Use a scan tool to confirm the code and check for other related codes.
• Repair any leaks in the exhaust system.
• Replace the differential pressure sensor if faulty.
• Replace or repair the DPF if damaged.
• Clear the code and test drive to ensure the issue is resolved.
• OBD-II scanner
• Pressure gauge
• Wrench set
• Exhaust leak detector
$200 - $1500
Moderate
• BMW 3 Series
• Mercedes-Benz C-Class
• Audi A4
• Regularly inspect the exhaust system.
• Perform routine maintenance on the DPF.
• Use high-quality fuel to reduce soot production.
Emission Control Issue
• Avoid driving with the Check Engine Light on for extended periods.
• Schedule regular maintenance checks.
• Use fuel additives that help clean the DPF.
Check with the vehicle manufacturer for specific warranty coverage related to emissions components.
This code has become more common with the increased use of DPFs in diesel vehicles to meet emission standards.
Moderate – While the vehicle may still be drivable, emissions could be affected, and ignoring the issue can lead to further damage.
Driving with a malfunctioning emission system may not meet legal emission standards and could result in fines or failed inspections.
• Engine at operating temperature
• Vehicle driven under various load conditions
The DPF is located in the exhaust system, typically under the vehicle, near the engine or along the exhaust pipe.
Q: What happens if I ignore this code?
A: Ignoring this code can lead to increased emissions, reduced fuel efficiency, and potential damage to the exhaust system.
Q: Can I drive my car with this code?
A: While the car may still be drivable, it's recommended to address the issue to avoid further damage and emissions problems.
High-End · Full-system diagnostics
A full-system bidirectional platform aimed at advanced DIY users and professional diagnostic workflows.
Network faults often require full-system access instead of a generic code reader alone.
View on Amazon
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.
View on Amazon
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.
View on AmazonThese are optional diagnostic tools, not guaranteed fixes. As an Amazon Associate I earn from qualifying purchases.