Why Do They Fail?

Exhaust Gas Pressure Sensors operate in extremely demanding conditions and are continuously exposed to high temperatures, pressure fluctuations and exhaust contaminants. Common causes of failure include:

• Sensor contamination caused by soot, carbon deposits and oil vapour accumulating within the sensor or pressure ports.
• Blocked pressure pipes or hoses preventing accurate pressure measurement and leading to incorrect ECU calculations.
• Heat-related degradation of the sensor electronics, housing or wiring due to prolonged exposure to extreme exhaust temperatures.
• Internal electrical faults resulting in signal loss, inaccurate readings or gradual sensor drift over time.
• Wiring and connector issues caused by heat, vibration, corrosion or poor electrical connections.
• Underlying DPF or emissions system faults that can be mistaken for sensor failure, leading to unnecessary replacement.

Because exhaust gas pressure sensor faults often present similar symptoms to blocked DPFs, damaged pressure pipes or EGR-related issues, accurate diagnosis should always include inspection of the complete emissions system.

Symptoms of a Failed Exhaust Gas Pressure Sensor

When an Exhaust Gas Pressure Sensor fails or provides inaccurate readings, a range of drivability and emissions-related issues may occur, including:

• Illuminated warning lights, including the Engine Management Light (MIL), DPF warning light or emissions system alerts.
• Failed or excessive DPF regeneration events, causing the filter to become overloaded or regenerate more frequently than necessary.
• Reduced engine performance and limp-home mode activation as the ECU limits engine output to protect emissions components.
• Diagnostic trouble codes (DTCs) relating to exhaust pressure plausibility, sensor performance or DPF efficiency, including common codes such as P2452 and P2002.
• Inaccurate DPF soot load calculations displayed on diagnostic equipment or scan tools.
• Increased fuel consumption caused by incorrect regeneration strategies and emissions system operation.

Because many of these symptoms can also be caused by blocked DPFs, damaged pressure pipes or EGR system faults, accurate diagnosis should always include inspection of the complete emissions system alongside sensor testing.

Fitting Tips

• Inspect and clean all pressure pipes and ports before replacing the sensor, as blockages caused by soot or carbon deposits are a common source of incorrect diagnosis.
• Replace any damaged, cracked or softened pressure hoses to prevent leaks and inaccurate pressure readings.
• Inspect wiring and connectors for signs of heat damage, corrosion or poor electrical connections before installation.
• Mount the sensor securely and ensure routing of pipes and wiring follows OE specifications to minimise vibration and heat-related stress.
• Clear stored fault codes and verify live data after installation, checking pressure values during both idle and loaded operating conditions.
• Allow the exhaust system to cool fully before removal or installation to avoid injury and prevent damage to surrounding components.

Not sure whether the fault lies with the sensor, pressure pipes or the DPF itself? Our TechASSIST team can help guide you through diagnosis, live data analysis and best-practice installation procedures.