Mitsubishi Pajero Diesel Particulate Filter DPF

The Diesel Particulate Filter (DPF) in Mitsubishi Pajero diesel models, especially Pajero IV (V88W, V98W) with the 3.2 DI-D (code 4M41) engine, is an essential emission control device. Introduced to meet Euro 4 and Euro 5 standards, it captures harmful soot particles from diesel exhaust gases in a ceramic body made of silicon carbide or cordierite. The trapped soot is then burned off by a regeneration process to reduce pollution.

The DPF is designed for Pajero IV models (V8W, V9W) with the 3.2 DI-D engine delivering 160-200 HP, produced up to May 2015 with Euro 4/5 compliance. It fits vehicles originally equipped with OBD and factory-fitted DPF systems. The filter material is either silicon carbide or cordierite, supplied with mounting kits and identified by OEM numbers like 1583A056 (compatible with FK11091, PP11091A/B/C). Positioned in the exhaust line after the catalytic converter and before the rear silencer, it can hold up to 60 grams of ash.

The DPF traps carcinogenic soot particles from diesel exhaust by forming a soot layer in its ceramic filter. Without cleaning, this layer clogs the filter.

• Automatic regeneration: The vehicle's system raises exhaust temperature using fuel injection or EGR valve adjustments to burn the soot. This can be tracked via OBD by monitoring soot levels.
• Passive regeneration: Driving at 60-80 km/h for 25-30 minutes helps reach the temperature needed to burn soot naturally.
• Forced active regeneration: Activated via diagnostic tools or at dealerships when clogging is detected.

Note that regeneration may cause engine oil dilution. Use high-quality fuel with additives, avoid short city trips, and regularly check the EGR valve to maintain DPF health.

Signs that your DPF may be defective or blocked include:

• Increased diesel fuel consumption
• Loss of engine power
• Illumination of Check Engine or DPF warning light
• Reduced engine or turbocharger performance

Maintenance and care for the DPF involve:

• Using fuel additives or DPF cleaning agents added to the fuel tank to help dissolve soot and particles.
• Performing regular driving cycles at highway speeds (60-80 km/h for 25-30 minutes) to promote passive regeneration.
• Forced regeneration using diagnostic tools at workshops or dealerships when necessary.
• Replacing the DPF every 120,000 to 170,000 km to avoid breakdowns.

Original new replacement parts are available matching OEM specifications and come with quality mounting kits.

Determining if your Pajero has a factory-fitted DPF can sometimes be done by inspecting the exhaust line for a ceramic filter positioned after the catalytic converter and before the rear silencer. Visible sensor connections and OBD diagnostics indicating soot levels are also clues. For precise confirmation, use the vehicle's VIN or refer to manufacturer specifications or professional diagnostics.

DPFs do not have a fixed expiry date but have a recommended replacement interval, usually between 120,000 and 170,000 kilometers. Their lifespan depends on driving habits, maintenance, and fuel quality. Regular regeneration and proper care significantly extend their operational time. Neglect or persistent short trips that prevent regeneration can cause premature clogging and failure.

Incorrect driving habits such as frequent short trips that don't heat the engine sufficiently can prevent regeneration, leading to excessive soot buildup and clogging of the DPF. Also, modifications like removing or deleting the DPF or ECU remapping can cause irreversible damage. Water or oil contamination in the exhaust, improper maintenance of the intercooler or EGR valve, and use of poor-quality fuel accelerate DPF failure. Such issues often trigger warning lights and reduce vehicle performance.

Always follow manufacturer recommendations for operation and consult your mechanic or dealers specialized in DPF systems for proper service and advice.