Exhaust Citroen DS4 (2011-2015)

Citroën DS4 diesel versions, especially engines like 1.6 e-HDi 115 hp and HDi 110 FAP, often face exhaust problems such as clogging of the DPF (Diesel Particulate Filter), incomplete regeneration, faulty sensors, issues with exhaust flaps, and leaks that cause unpleasant smells or smoke.

The "DPF nearly clogged" warning often appears after 30,000 to 35,000 km, caused by the accumulation of diesel particulates and PSA additive residues. Proper regeneration requires sustained high temperature (400-450°C) for about 10-15 minutes at highway conditions (75-100% load, 3000-3500 rpm, vehicle fully loaded with accessories on). Excessive clogging triggers limp mode requiring garage intervention for physical cleaning or DPF replacement.

Common signs of sensor failure, such as the exhaust backpressure sensor, include engine warning lights on, visible smoke upon acceleration, and failure of DPF regeneration. Exhaust flap malfunctions require professional diagnosis and replacement by a mechanic to restore proper function.

Drivers may notice strong exhaust odors accompanied by irregular engine behavior and engine warning indicators, typically pointing to leaks or issues with DPF or fuel injection. Blocked exhaust systems can cause black smoke, unusual noise, and loss of power, especially in diesel HDi 110 FAP models, which should be diagnosed professionally.

The DS4 (2011-2018) has recurring exhaust system issues including DPF clogging, NOx emissions, and other antipollution system faults worsened by carbon build-up. Several recalls have addressed defects such as AdBlue crystallization deforming tanks/injectors, vacuum pump brake failures, and starter cable shorts related to the EGR valve. These recalls mostly concern diesel engines like 1.6 e-HDi 115 and HDi 110.

Manual DPF regeneration can be performed by driving at sustained highway speeds (e.g. 140 km/h in 4th gear) but risks entering limp mode if too late. Diagnostics using tools like MyCarly can read sensors and DPF status. Repairs may involve cleaning or replacing the DPF, sensors, exhaust flaps, or injectors. Professional workshops and services like Fixter provide quotations and repair services. Regular long drives help natural regeneration and maintaining additive levels prevents clogging.

Preventive measures include taking long trips on highways to allow the DPF to regenerate naturally and scheduling additive fluid replacements as part of regular maintenance. Avoiding short trips and stop-and-go traffic can also reduce the risk of DPF clogging.

Useful resources include specialised automotive forums such as forum-auto.matmut.fr for DPF blockages, reliability sites with user testimonials, and diagnostic communities like MyCarly for sensor and health status. Repair platforms like Fixter and professional diagnostic centres provide technical support and service. Checking official recalls based on your vehicle VIN at Citroën dealerships is recommended.